-NRLF 


D   E   SbT   144 


/BERKELEY 

LIBRARY 

UNIVERSITY  OF 
V      CAIIFORNIA 


-     - ,         — 

;- 


t 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 


GEOLOGY  LIBRARY 
IN  MEMORY  OF 

PROFESSOR 
GEORGE  D.  LOUDERBACK 

1874-1957 


: 


RESEARCH  IN  CHINA 

IN   THREE   VOLUMES   AND   ATLAS 


VOLUME    TWO 


SYSTEMATIC  GEOLOGY 


by 
BAILEY  WILLIS 


WASHINGTON,  D.  C. 

PUBLISHED  BY  THE  CARNEGIE  INSTITUTION  or  WASHINGTON 

JULY,  1907 


GEOLOGICAL  SCIESCES  LIB 


CARNEGIE  INSTITUTION  OF  WASHINGTON 
PUBLICATION  No.   54  (VOLUME  2) 


PRESS  OF  GIBSON  BROTHERS, 
WASHINGTON,  D.  C. 


GIFT 


CONTENTS. 


PAOB. 

INTRODUCTION  ...................  v 

CHAPTER  I.  —  ARCHEAN   ................. 

CHAPTER  II.  —  PROTEROZOIC   ................ 

Proterozoic  Strata    .  ............... 

Wu-t'ai  System  (Eo-Proterozoic)  .......       ......  4 

Hu-t'o  System  (Neo-Proterozoic)          ............  7 

Pre-Sinian  Rocks  of  Central  China       ............  13 

Ancient  Metamorphic  Rocks  beyond  China                                       v       .....  2O 

Pre-Sinian  Diastrophism         ...............  24 

Pre-Sinian  Unconformity        ...............  31 

CHAPTER  III.  —  EARLY  PALEOZOIC        ......       •       •    '   ...... 

Sinian  System  (Cambro-Ordovician)     ............. 

The  name  and  its  application         ........  35 

Sinian  in  China         ...............        • 

Lower  Sinian     .        .        ..............  37 

Nan-t'ou  tillite         ..............    _  •   ^  39 

Middle  Sinian,  Kiu-lung  group       ............  4° 

Upper  Sinian      ................  42 

Sinian  in  general      .........  43 

Post  -Sinian  Diastrophism        ...............  49 

CHAPTER  IV.  —  MIDDLE  PALEOZOIC       .......  ...... 

Siluro-Devonian  Strata  of  China    .......  .....  53 

Middle  Paleozoic  Strata  beyond  China  ......  59 

Middle  Paleozoic  Diastrophism      ........... 

Pre-Carboniferous  Unconformity  ..............  67 

CHAPTER  V.  —  LATE  PALEOZOIC     ......... 

Carboniferous  Strata       ................ 

Marine  Carboniferous       .......        ........ 

Continental  Carboniferous      ..........        ....  75 

CHAPTER  VI.  —  PERMO-MESOZOIC  .... 

Transition  from  Paleozoic  to  Mesozoic  ............. 

Theoretical  considerations      ............. 

Permo-Triassic  Strata     ................ 

Angara  series    ......... 

Central  China    ...........  83 

Jurassic      ...................  °6 

Permo-Mesozoic  Diastrophism       ..............  °9 

CHAPTER  VII.  —  CONTINENTAL  ASIA     ..............          95 

Cretaceous  .................... 

Tertiary  and  Quaternary        ............... 

CHAPTER  VIII.—  CONTINENTAL  STRUCTURE  OF  ASIA 

Hypothesis  of  Continental  Structure     ............          "5 

Continental  Elements  of  Asia         ............. 

Tangential  Compression  ............... 


039 


LIST  OF   ILLUSTRATIONS. 

PAGB. 

Plate  i. — Geologic  Map  of  Parts  of  CM-li  and  Shan-si,  after  F.  von  Richthofen,  Bailey  Willis, 

and  Eliot  Blackwelder i 

Plates  2  and  za. — Geologic  Route  Map,  Shen-si  and  Ssi'-chuan,  after  Bailey  Willis  and  Eliot  Black- 
welder  i 

Plate  3. — Southern  Asia  during  the  Proterozoic  Era 35 

4. — Southern  Asia  during  the  Sinian  Period 53 

5. — Southern  Asia  during  the  Middle  Paleozoic 71 

6. — Southern  Asia  during  the  Carboniferous  Period 77 

7. — Hypsometric  Map  of  China  and  Adjacent  Regions,  showing  the'.Effects  of  Tertiary  and 

Quaternary  Diastrophism  without  regard  to  Results  of  Erosion 115 

8. — Continental  Structure  of  Asia 123 


ERRATA. 

Page  17,  line  5,  read  1903-04  for  1904-05. 
Page  49,  line  24,  read  later  for  late. 


INTRODUCTION. 


The  expedition  to  China  carried  out  in  1903-04  under  the  auspices 
of  the  Carnegie  Institution  of  Washington  gathered  certain  observations 
relating  to  the  geology  of  that  country,  which  are  stated  in  detail  under 
the  general  subject  of  descriptive  geology,  in  volume  I,  part  I,  of  these 
contributions.  The  same  material  is  treated  in  this  volume,  but  from  the 
standpoint  of  systematic  continental  history.  Repetition  has  been  avoided, 
so  far  as  is  consistent  with  the  presentation  of  the  general  subject.  Other 
sources  of  published  information  have  been  freely  consulted  and  are  referred 
to  in  connection  with  the  discussions. 

The  subject-matter  of  this  volume  is  classified  primarily  according  to 
geologic  eras  or  periods,  and  secondarily  by  broad  areas  of  which  China 
proper  is  the  central  region.  Thus  the  reader  will  find  that  each  chapter 
treats  of  the  geographic  condition  of  southeastern  Asia  during  a  particular 
age,  and  that  successive  chapters  trace  the  sequence  of  changes  from  age  to 
age.  Only  the  great  events  of  continental  history  are  distinguishable  on 
the  basis  of  existing  knowledge,  but  they  suffice  to  show  that  the  present 
continent  is  an  aggregation  of  land  masses  which,  from  time  to  time,  have 
been  forced  into  union  with  one  another.  This  generalization  has  already 
been  stated  by  [Suess,  who,  in  cooperation  with  Neumayer,  developed  the 
recognition  of  the  great  mediterraneans  which  formerly  divided  Eurasia. 

This  study  of  Asia  has  been  carried  on  with  comparative  studies  of 
North  America  and  Europe,  and  has  led  to  theoretical  views  regarding 
continental  structure  and  development  which  have  a  broad  application. 
They  are  briefly  stated  in  a  closing  chapter. 

Many  associates  have  helped  me  toward  an  understanding  of  the  prob- 
lems involved,  and  I  desire  to  express  my  appreciation  of  aid  received  from 
geologists  and  physicists  alike.  An  especial  debt  is  due  the  two  great 
leaders  in  the  modern  advance  of  geological  philosophy,  Chamberlin  and 
Suess,  from  whose  works  and  personal  suggestion  I  have  derived  the 
highest  inspiration.  Their  assistance  is  none  the  less  earnestly  appreciated 
because  I  have  been  compelled  to  a  somewhat  divergent  view  in  theoretical 
questions  of  continental  development. 

BAILEY  WILLIS. 
WASHINGTON,  D.  C,  February  25,  1907. 

v 


CHI-LI       SHAN  -SI 


BE  SEARCH  IN    CHIJST 


Cornpiled  fro  m  S  u  rvey  s  oF 
I903-04and  otherSources 


Willis  mid  Ulu<:kwflil.-i- 


(  it-all  >t/i<-    Ml  If  <>l '  fMll-t-S  (J. 

ChJi-H  ancL  Shaii  «/' 


10          5  o 


2O  30 


ROUTE .  JANUARY  AND  FEBRUARY 


LEGEND 
SEDIMENTARY  ROCKS 


PLATE     1 


Geolo6y  by  Bailey  Willis 

and  Eliot  Blackwelder,  I903-O4- 

and  F.von  Richthofen,  I87O 


lr-l,,;-ly  ///«(>•  limfuliiir  in 
I,-,I,M  mtl,  sltttr  <I71<Z 

auartaeUftprerm  slat* 

*  I/ft   Oui,!,r,l»  ,,r.tlhwll 
Lii>^>i'«ft*ilr,u'i<l 


UNCONFORMITY 
METAMORPHIC  ROCKS 


Wu-t  ai 
scliists 

(,'hluritr-avhiirt  with  </i 


qunrtx 
n  inter 
.l  iVUo 
ritr.  aohittta; 


UNCONFORMITY 


O 

N 
O 

X 

UJ 

O 

cc 

Q- 


Tai-sli,-in 
complex: 

'tts  .i/i./  .v.-A/.v/  .7i//-/7 
mm  Of^ffttt  ./uni 
tiu^':  with  itituii 
.Hi- 1  I'fhfr'i/itrTt.tiirx  , 


UJ 
I 

O 
IT 


SHEN-SI 


RESEARCH  IN   CHINA 


PLATE   ^ 


30' 


Wu-kiing-luen 


Cbucra.-chj  hi 

I  fit  n>' 


nmriaita  of sand  -in.! 


Won-k  u  ng-m  i  j 


UNCONFORMITY 


UNCONFORMITY 


flight  gray  hornblende- 
buvtite.  -yriuiite  ,-  niassiyt* 
•  uii/  locally  [torfihvritu: 


and 

.    Basjc 
iiitrusives 


greenstone- 
and  amphibolic 
und  nioaaiye  intrusions) 


i-ts'iitui  liioii 

2OO' 


Sxa-ohou. 

schists 

/v.  t  shale 
thin  mitri 
urn/ anil  uttered.- to 


Siiii-yaiig-liien 


UNCONFORMITY* 


aciaasified 

Paleozoic 

schists  and  gnejsse 

-schist  and 
white  biotitio  marble, ) 

' 


108*00' 


108*30' 


I09"30' 


GEOLOGIC  ROUTE    MAP    I9O4 


10  .*> 


Scale    1:1000000 
in  go 


.<•    .Mil*-M 


5  *> ID ap 30 iO 50 


Geology  by  Bailey  Willis 
and  Eliot  BlacUwelder. 


AHOEMfl,CO    MALTIMOnB 


GHITAN 


RESEARCH  IN    CHINA 


PLATE  2? 


lOB'oo' 


no*oo' 


Si  ui-yang-liieii 


Wri-ahan 

limestone 

f  blue  -blank  tutif-stvn*  with 
lit,  "  -A-  ttrgiUite  in  the,  north 


to  in,i.\xn;- 

and  anit'  limestone  it-fin 
icJ?  chert  in  the  south  , 


!.•  H-hiit  ft, •/iijrt'tisf  twil 

i 'I,,, 


Sin  t  HII 
slate  iunl  sliale 

'  siln->><nt&  any  to  green  shale 
iii  the  north  :ijtt>eniah  to 


shttlf  in  *ft«  south, 
n-/tiTt  fH-lnatoa 
iiff>h0Wfi  n& 
i  'lii>n  -p'iny-hi&n. 


T'an-n  m-siiu-pi 


UNCONFORMITY 


Ta  uin<5-hieai 

700' 


f'-hha-itf  -st-hist,  rith 


limratnne  and  t/iuirtxitej 


lOB'OO' 


108*30' 


GEOLOGIC    ROUTE     MAP   19OA- 


S«-;tlc     i :  in,..  KM  »o 


Geology  by  Bailey  Willis 
and  Eliot  Blackwelder. 


10       r.       < . 


CHAPTER  I,— ARCHEAN. 


The  term  Archean  has  been  used  in  Asiatic  geology  by  different  writers 
to  cover  various  metamorphic  but  usually  ancient  rocks.  Generally  it  is 
applied  to  any  highly  metamorphic  or  igneous  rocks  which  are  older  than 
the  oldest  clearly  recognized  sediments  of  any  particular  district.  In  the 
literature  "Archean"  thus  covers  rocks  which  range  in  age  from  the  very 
earliest  pre-Paleozoics  observed  in  the  continent  to  Paleozoic,  or  possibly 
even  Mesozoic  strata,  where  these  have  been  greatly  altered.  Moreover, 
the  intrusives  have  commonly  been  grouped  with  the  schists,  although 
they  are  certainly  somewhat  younger,  and  it  is  sometimes  difficult  to  say 
how  much  younger.  Thus,  granites  which  reav  be  of  Paleozoic  or  Mesozoic 
age  are  classed  as  pre-Paleozoic. 

In  these  volumes  the  term  Archean  is  applied  to  a  basal  mass  of  gneisses 
and  schists,  which  is  also  designated  the  T'ai-shan  complex.  It  is  regarded 
as  basal  because  it  underlies  all  other  recognized  groups  and  is  separated 
from  them  by  an  unconformity  of  a  most  distinct  and  profound  character; 
moreover,  it  is  fundamental  among  rock  masses  known  at  the  surface, 
because  it  is  itself  apparently  bottomless.  Nothing  distinct  from  it  and 
older  than  it  has  as  yet  been  identified. 

The  T'ai-shan  complex  is  not  everywhere  followed  by  rocks  of  the 
same  age,  the  geologic  record  being  incomplete  in  China  as  elsewhere.  In 
the  Wu-t'ai  district  of  northern  Shan-si,  it  underlies  the  Shi'-tsui  group  of 
the  Wu-t'ai  schists,  probably  the  oldest  group  of  sedimentary  deposits 
identified  in  Asia.  The  most  probable  rough  correlation  places  this  sequence 
in  parallelism  with  the  lower  Huronian  and  Keewatin  of  the  Lake  Superior 
region  of  North  America.* 

In  northeastern  China,  in  the  province  of  Shan-tung,  is  the  type  locality 
of  the  T'ai-shan  complex,  Mount  T'ai.  The  most  ancient  rocks  are  there 
overlain  by  Lower  Cambrian  strata  and  the  pre-Cambrian  sediments  are 
wanting;  correlation  with  the  Archean  of  the  Wu-t'ai  district  is  based  on 
similarity  of  lithologic  and  structural  characters,  which  are  common  to  all 
the  occurrences  which  we  have  classed  as  T'ai-shan  and  are  not  shared  by 
any  other  rock  masses  of  known  superior  position  in  the  geologic  scale. 

*  Report  of  special  conimittec  for  the  Lake  Superior  Region,  Chicago  Journal  of  Geology,  vol.  xiu, 
p.  89,  1905. 

i 


2  RESEARCH   IN   CHINA. 

The  lithologic  and  structural  characters  of  the  T'ai-shan  complex 
are  those  of  the  Archean  of  the  Lake  Superior  region  of  North  America, 
as  defined  by  Van  Hise.  The  rocks  are  chiefly  metamorphic  schists  and 
gneisses  of  indeterminate  original  character;  associated  with  them  is  a 
large  proportion  of  metamorphosed  igneous  rocks  and  a  very  small  pro- 
portion of  metamorphosed  sediments;  and  the  metamorphics  are  intruded 
by  granites,  which  are  relatively  young,  though  in  large  part  probably 
pre-Cambrian. 

The  structure  of  the  gneisses  and  schists  is  exceedingly  intricate;  it 
is  characterized  by  a  universal  schistosity;  by  a  common  banding;  by  com- 
plex shearing,  thinning,  thickening,  plication,  and  flow  of  bands;  and  such 
intricate  arrangement  of  the  very  variable  petrographic  facies  of  the  schists 
and  gneisses  as  makes  impossible  any  structural  study  by  usual  strati- 
graphic  methods. 

These  lithologic  and  structural  peculiarities  of  the  T'ai-shan  complex 
serve  to  distinguish  it  unmistakably  from  the  oldest  pre-Cambrian  sedi- 
ments, the  Wu-t'ai  system,  even  though  the  latter  are  intensely  metamor- 
phosed. 


CHAPTER  II.— PROTEROZOIC. 


PROTEROZOIC  STRATA. 

We  recognize  two  principal  systems  of  stratified  rocks  of  the  Protero- 
zoic  era  in  northern  China,  the  Wu-t'ai  and  the  Hu-t'o  or  Nan-k'ou  systems. 
The  Wu-t'ai  was  observed  and  named  by  von  Richthofen ;  the  other  he  did 
not  distinguish  from  the  Sinian,  of  which  he  thought  it  a  conformable  part, 
and  he  described  it  as  "Untersinisch."  In  certain  sections  and  probably 
generally,  there  is  an  unconformity  between  the  "Untersinisch"  and  the 
"Obersinisch,"  and  it  seems  desirable  to  separate  them  by  restricting  the 
term  Sinian  to  upper  or  Obersinisch  and  giving  a  new  name  to  the  lower 
or  Untersinisch.*  Nan-k'ou  is  an  appropriate  name,  which  may  be  applied 
if  we  correctly  understand  von  Rich thof en's  section  at  the  celebrated  pass 
northwest  of  Peking.  Hu-t'o  is  a  name  we  gave  to  a  series  which  is 
probably  the  equivalent  of  the  Nan-k'ou,  though  it  differs  somewhat  in 
the  character  of  the  strata.  The  matter  is  discussed  in  a  later  paragraph. 

Proterozoic  rocks  are  best  exposed  in  China,  so  far  as  yet  known,  in  a 
mountain  range  in  northern  Shan-si,  called  the  Wu-t'ai-shan.  This  name, 
which  means  Five  Platform  Mountains,  is  derived  from  the  five  highest 
summits  in  the  region,  Pei'-t'ai  or  North  Table  having  an  altitude  of  10,045 
feet.  The  range  is  deeply  incised,  and  the  canyons  expose  remarkably 
distinct  sections  of  ancient  metamorphic  rocks,  comprising  the  basal  or 
T'ai-shan  complex  (Archean)  and  the  Wu-t'ai  system,  eo-Proterozoic. 
The  latter  is  thought  to  be  roughly  correlative  in  age  and  duration  and 
complexity  with  the  Huronian  of  Canada. 

On  the  southeastern  flank  of  the  Wu-t'ai-shan  is  a  wide  area  of  hills 
and  valleys,  which  we  have  called  the  Northern  Loess  Basins.  The  general 
altitude  is  3,500  to  5,000  feet  above  sea.  Rocks  of  the  early  Proterozoic, 
Wu-t'ai,  system  constitute  part  of  the  surface,  but  a  younger  pre-Cambrian 
system  of  but  slightly  altered  quartzites,  slates,  and  siliceous  limestones 
covers  a  larger  area.  This  neo-Proterozoic  system  we  have  called  the 
Hu-t'o,  a  local  name,  which  may  ultimately  be  replaced  by  the  term  Nan- 
k'ou  of  von  Richthofen  or  that  of  Nan-shan  of  Loczy. 

In  view  of  the  better,  though  still  incomplete,  knowledge  which  we 
have  of  the  Proterozoic  in  the  Wu-t'ai  as  compared  with  notes  of  occur- 
rence of  similar  rocks  elsewhere,  we  may  take  the  Wu-t'ai  sections  as  types. 

*In  a  personal  conference  in  Berlin,  March,  1905,  von  Richthofen  agreed  orally  to  the  desirability  of 
making  this  distinction,  but  his  views  were  not  put  in  writing,  so  far  as  I  am  aware. 


4  RESEARCH    IN   CHINA. 

WU-T'AI  SYSTEM  (EO-PROTEROZOIC). 

Rocks  of  the  Wu-t'ai  system  constitute  much  of  the  Wu-t'ai-shan,  a 
short  but  high  mountain  range  in  northern  Shan-si,  longitude  113°  30'  E., 
latitude  39°  N.  Von  Richthofen  crossed  the  mountains  in  December, 
1871,  and  clearly  observed  the  existence  of  a  series  of  strata  which  he  had 
not  previously  seen  in  thewcourse  of  his  extended  journeyings;  nor  are  they 
elsewhere  known  in  equal  mass.  During  the  stormy  December  weather 
which  he  met  the  conditions  were  most  unfavorable  for  observation,  and 
his  route  crossed  only  a  part  of  the  Wu-t'ai  rocks,  that  mass  of  chlorite 
schists  which  we  consider  the  upper  part  and  call  the  Si-t'ai  formation. 
The  lower  series  of  mica  schists,  quartzites,  and  marbles  he  did  not  see. 

Von  Richthofen  placed  the  Wu-t'ai  system  in  the  Huronian,  using 
the  latter  term,  as  was  commonly  done  thirty  years  ago,  to  suggest  pre- 
Paleozoic  metamorphic  rocks  of  green  color.*  He  does  so  with  reserve, 
however,  and  the  stricter  usage  of  the  term  as  it  is  now  adoptedf  does  not 
permit  us  to  maintain  an  exact  correlation.  Yet  there  is  a  certain  paral- 
lelism in  stratigraphic  position  and  history,  as  well  as  likeness  in  rocks, 
which  invites  comparison  of  the  Wu-t'ai  and  the  Huronian,  as  will  appear 
in  stating  the  facts  as  we  now  understand  them. 

Our  own  opportunities  for  study  of  the  Wu-t'ai  system  were  limited 
practically  to  a  single  section  and  a  few  isolated  localities.  In  volume  i 
we  have  stated  our  inference  regarding  the  stratigraphic  sequence  and 
structure  as  provisional  only,  and  we  commend  to  some  future  investigator 
the  almost  unequaled  exposures  of  ancient  sedimentary  and  igneous  rocks 
which  represent  one  of  the  earliest  intelligible  records  of  Asiatic  history. 

A  provisional  classification  of  the  Wu-t'ai  and  limiting  systems  in  the 
type  locality  is  as  follows: 

Hu-t'o  system  Tung-yu  limestone  1          s,ates_    limestonei    and   quar,zite. 

(Neo-Prolerozoic)  T6u-ts'un  slates 

Unconformity 

I  Si-t'ai  series  Chiefly  chlorite  schist;  quartzite  conglom- 

erate  at  the  base. 
Unconformity 
..  u-l  >.   ,,,.,.^,,1 

(Eo-Proterozoic)          1  Nan-t'ai  series  Siliceous    marble,    jasper,  quartzite,  and 

schist. 

Unconformity 

L  Shi'-tsui  series  Mica  schists,  gneiss,  magnetite  quartzite, 

and  basal  feldspathic  quartzite. 

Unconformity 
T'ai-shan  complex  Basal    complex    of  varied  gneisses   and 

(Archean)  younger  intrusives. 

A  brief  account  of  the  successive  elements  of  the  Wu-t'ai  section  fol- 
lows (see  atlas  sheet  DI  and  plate  xvm,  volume  i,  part  i). 

*China,  vol.  n,  !p.  377. 

t  Report  of  International  Committee,  Chicago  Journal  of  Geology,  vol.  xin,  1905. 


WU-T'AI  SYSTEM,  EO-PROTEROZOIC.  5 

That  there  is  an  unconformity  at  the  base  of  the  Shi'-tsui  series,  sepa- 
rating it  from  the  T'ai-shan  complex,  we  do  not  doubt.  The  distinction 
between  the  stratified  schists  and  quartzites  of  sedimentary  origin  and  the 
very  intricate  complex  of  parallel  bedded  injection  gneisses  is  decided  when 
they  are  contrasted  in  extensive  sections.  But  the  exact  contact  between 
the  two  is  not  readily  recognized.  In  a  ravine  south  of  the  T'ai-shan-ho 
we  found  a  peculiar  quartzite  containing  large  crystals  of  red  feldspar, 
which  is  a  recrystallized  arkose,  occurring  at  or  near  the  base  of  the  Shi'-tsui 
series,  on  or  close  to  the  T'ai-shan  gneiss,  from  which  the  material  was 
probably  derived  by  erosion.  The  immediately  underlying  stratum  is  a 
mica  schist  of  indeterminate  origin.  The  feldspathic  quartzite  grades 
upward  through  quartzite  containing  some  mica  and  but  little  feldspar, 
into  mica  schists,  which  present  great  variety  of  mineralogical  composition 
and  are  in  turn  succeeded  by  quartzites  which  are  in  part  magnetic.  The 
section  of  sediments,  which  has  a  length  of  eight  miles,  is  interrupted  by 
a  mass  of  augen-gneiss  that  is  probably  intrusive.  The  dip  of  the  Shi'-tsui 
strata  in  this  section  is  from  30°  to  70°  to  the  northwest,  and  the  repetition 
of  the  quartzite  on  two  sides  of  a  great  body  of  mica  schists  is  such  that 
the  probable  structure  is  a  syncline  overturned  toward  the  southwest. 

The  augen-gneiss  above  referred  to  extends  for  three  miles  along  the 
T'ai-shan-ho.  It  has  the  uniformity  of  composition  of  a  batholite  and 
appears  to  be  an  intrusive  which  has  suffered  shearing  and  metamorphism 
with  the  sedimentary  Wu-t'ai  rocks.  Northwest  of  it  occur  the  strata  of 
the  Si-t'ai  and  Nan-t'ai  groups. 

Nan-t'ai  and  Si-t'ai  are  two  of  the  five  peaks  of  the  Wu-t'ai-shan, 
each  of  which  is  composed  chiefly  of  the  strata  named  after  it. 

Strata  of  the  Nan-t'ai  group  are  siliceous  marble,  gray  to  black  or 
red  quartzites,  and  schists,  chiefly  of  chlorite  and  muscovite.  They  are 
also  garnetiferous  and  staurolitic.  They  occur  on  the  southeast  slope  of 
the  Wu-t'ai  range  and  are  well  exposed  in  the  canyons  above  Shang-ho- 
miau.  The  structure  shows  two  or  more  closed  synclines,  overturned 
toward  the  south,  and  overthrusts  which  eliminate  the  anticlines.  The 
sequence,  as  we  interpret  it,  consists  of  siliceous  and  muddy  sediments  below 
and  calcareous  deposits  above.  It  may  be  continuous  with  or  distinct 
from  the  Shi'-tsui.  The  two  groups  of  rocks  were  not  seen  in  contact. 

The  Si-t'ai  group,  comprising  most  if  not  all  'of  the  sequence  seen  by 
von  Richthofen,  forms  the  mass  and  northern  slope  of  the  Wu-t'ai-shan. 
It  is  a  great  body  of  green  schists,  chiefly  chloritic,  with  beds  of  quartzite 
containing  magnetite,  and  coarse  conglomerate  of  quartz  and  quartzite 
cobbles  at  the  base;  all  as  he  described  it.*  The  relations  with  the  Nan- 
t'ai  group  are  well  exposed  in  the  canyons  on  the  south  slope  of  the  range. 

*  China,  vol.  n,  p.  364. 


6  RESEARCH    IN  CHINA. 

We  there  find  the  conglomerate  duplicated  by  overthrust,  but  overlying  in 
regular  sequence  the  Nan-t'ai  quartzites,  and  grading  from  conglomerate 
through  quartzite  upward  to  schist,  after  the  fashion  of  a  passage  from 
basal  conglomerate  to  fine  muddy  sediments.  The  pebbles  in  the  conglom- 
erate consist  chiefly  of  quartz  and  quartzite,  the  latter  being  of  varieties 
that  occur  in  the  Nan-t'ai  group,  together  with  some  of  granite.  Hence  we 
infer  that  the  rocks  below  the  Si-t'ai  had  been  folded  and  eroded  before 
that  series  was  deposited.  The  conglomerate,  consisting  as  it  does  almost 
entirely  of  large  rounded  quartz  and  quartzite  pebbles,  contains  the 
remains  of  a  deposit  that  had  been  concentrated  from  a  more  complex 
constitution.  Before  metamorphism  it  may  have  closely  resembled  the 
bed  of  quartz  cobbles  found  at  the  base  of  the  Potomac  formation  of  the 
Atlantic  coast,  and  may  have  resulted,  as  that  deposit  did,  from  a  prolonged 
cycle  of  erosion  which  ended  in  consequence  of  a  marine  transgression  across 
a  peneplain.  Moreover,  in  the  western  part  of  the  Wu-t'ai-shan,  no  groups 
corresponding  to  the  Shi-tsui  and  Nan-t'ai  groups  were  seen  between  the 
T'ai-shan  complex  and  Si-t'ai  schists.  This  fact  and  the  presence  of  the 
granite  pebbles  in  the  conglomerate  suggest  an  overlap  of  Si-t'ai  strata 
beyond  the  older  Proterozoic  rocks. 

The  greater  part  of  the  Si-t'ai  group  consists  of  green  schists  colored 
chiefly  by  chlorite.  Stratification  is  obscured  by  schistosity  and  the  struc- 
ture can  not  readily  be  made  out.  It  is  probable  that  several  isoclinal  folds 
occur,  overtumed  toward  the  south  and  separated  by  overthrust  faults. 

On  the  summit  of  Pei'-t'ai  is  a  small  area  of  biotite  gneiss,  which  may 
be  the  highest  stratum  of  the  Si-t'ai  group  preserved  in  a  syncline,  but  we 
were  not  able  to  determine  conclusively  what  the  relations  to  the  adjacent 
green  schists  actually  were.  The  gneiss  may  be  an  intrusive  body. 

Returning  to  the  analogy  which  exists  between  the  Wu-t'ai  and  Huron- 
ian  systems,  I  may  point  out  some  of  the  parallel  relations.  The  Lower 
Wu-t'ai  (Shi'-tsui  group)  rests  unconformably  upon  the  basal  T'ai-shan 
complex,  as  the  lower  Huronian  does  on  the  Archean  (Keewatin)  gneiss. 
The  Nan-t'ai  group  overlies  the  Shi-tsui  and  may  be  separated  from  it  by 
an  unconformity,  as  the  middle  Huronian  is  from  the  lower.  The  two 
series  were  similarly  composed  of  siliceous,  clayey,  and  ferruginous  sedi- 
ments, which  have  undergone  intense  metamorphism  and  become  schists  of 
varied  constitution.  The  upper  Wu-t'ai  (Si-t'ai  group)  is  unconformable 
to  the  middle  Wu-t'ai  as  the  upper  Huronian  is  to  the  middle  Huronian. 
The  upper  group  in  each  case  consists  largely  of  chloritic  schists  associated 
with  ferruginous  quartzites.  [Both  the  Wu-t'ai  and  the  Huronian  series 
have  been  affected  by  some  igneous  intrusions,  which  occurred  before  the 
strata  were  deformed  by  shearing,  and  also  penetrated  by  later  dikes. 
These  are  but  analogies,  yet  they  serve  to  suggest  a  parallel  in  the  ancient 


LATER   PROTEROZOIC.  7 

history  of  Asia  and  North  America,  which  extends  to  successive  events  of 
erosion,  deposition,  and  deformation.  The  general  relations  to  the  Archean 
and  neo-Proterozoic  are  similar  in  both  continents,  and  the  effects  may  well 
have  been  due  to  a  general  terrestrial  cause  which  became  active  at  about 
the  same  times,  in  regions  remote  from  one  another. 

Before  discussing  the  occurrence  elsewhere  in  Asia  of  pre-Cambrian 
rocks,  which  may  be  equivalent  to  the  Wu-t'ai,  I  describe  the  next  younger, 
the  Hu-t'o  system. 

HU-T'O  SYSTEM  (NEO-PROTEROZOIC). 

All  of  the  rocks  of  the  Hu-t'o  system  are  sedimentary  strata :  conglom- 
erate, quartzite,  shale,  and  limestone,  which  resemble  the  unmetamorphosed 
Paleozoic  rocks  more  nearly  than  they  do  the  Wu-t'ai  schists.  The  physi- 
cal events  which  intervened  between  the  close  of  the  Wu-t'ai  period  and 
the  beginning  of  the  Hu-t'o  involved  greater  changes  and  probably  longer 
time  than  those  which  occurred  'after  the  Hu-t'o  and  before  the  Sinian; 
but  the  presence  of  a  rich  fauna  in  the  Sinian  seas  distinguishes  that  period 
from  the  preceding  time,  during  which  the  life  forms,  though  probably 
numerous,  did  not  generally  become  fossil.  The  nearest  relations  of  the 
Hu-t'o  system  are  with  the  Belt  terrane  of  Montana,  and  it  is  probable  that 
pre-Cambrian  fossils*  such  as  have  been  found  in  the  Belt  may  eventually 
be  discovered  in  the  Hu-t'o. 

The  Hu-t'o  rocks  occur  in  typical  development  in  the  district  of  Wu- 
t'ai-ihen,  in  northern  Shan-si,  where  they  form  the  southwestern  part  of  the 
Wu-t'ai-shan  and  the  hills  about  the  Northern  I/oess  Basins  as  well  as  along 
the  Hu-t'o  river.  They  occupy  a  broad  synclinorium  and  lie  between  the 
Wu-t'ai  schists  and  Sinian  strata,  in  unconformable  relations  to  both 
systems.  Although  the  contact  with  the  underlying  Wu-t'ai  series  must 
be  extensively  exposed  in  the  mountains  southwest  of  the  upper  T'ai-shan-ho 
and  also  north  of  the  Loess  Basins,  we  did  not  see  it.  It  was  covered  by 
loess  in  each  of  the  sections  along  which  we  crossed  it,  and  we  did  not  recog- 
nize the  distinct  position  of  the  unfamiliar  Hu-t'o  rocks  in  time  to  search 
for  the  contact.  There  can,  however,  be  no  doubt  of  an  unconformity 
between  the  schists  of  the  Wu-t'ai  and  the  little-altered,  slightly  slaty  beds 
of  the  Hu-t'o.  After  the  Wu-t'ai  sediments  had  been  deposited  they  were 
folded,  depressed  by  folding  or  subsidence  to  a  notable  depth,  intruded  by 
large  igneous  masses,  and  deformed  under  great  pressure,  so  that  their 
original  structure  was  replaced  by  schistosity  and  their  constituents  were 
recrystallized.  The  Hu-t'o  rocks  suffered  none  of  these  changes.  They 
were  deposited  only  after  the  schists  had  been  exposed  by  uplift  and  deep 
erosion.  Obviously  an  interval  of  the  first  magnitude  intervened. 

*Pre-Cambrian  fossiliferous  formations,  C.  D.  Walcott,  Bull.  G.  S.  A.,  vol.  x,  p.  199,  1899. 


8 


RESEARCH   IN   CHINA. 


Observations  of  the  contact  between  the  Hu-t'o  and  the  overlying 
Sinian  show  clearly  that  the  former  were  folded,  intruded  by  dikes,  and 
eroded,  before  the  latter  were  laid  down.* 

The  Hu-t'o  strata  apparently  constitute  a  sequence,  which  consists  of 
conglomerate  and  sandstone,  clay  slates,  and  siliceous  calcareous  strata. 
The  entire  series  is  thinly  bedded  and  the  three  elements  (sands,  clays, 
and  carbonates)  occur  interbedded.  In  the  type  locality  we  observed  a 
number  of  partial  sectionsf  which  we  could  not  connect  on  account  of  the 
extensive  covering  of  the  Huang-t'u,  the  loess  formation.  The  sandy  rocks 
appear  to  preponderate  near  the  base  and  the  limestones  increase  in  pro- 
portion toward  the  top.  This  distinction  appeared  to  be  sufficiently  marked 
to  separate  a  lower  argillaceous  group  from  an  upper  calcareous  one,  and 
we  have  described  the  former  as  the  Tou-ts'un  slates  and  the  latter  as  the 
Tung-yu  limestone.  The  division  has  local  significance  only. 

The  Tou-ts'un  slates  comprise  the  lowest  beds  of  the  Hu-t'o  series  and 
have  a  thickness  of  not  less  than  3,500  feet,  1,000  meters;  they  may  reach 
5,000  feet,  1,800  meters.  The  principal  strata  are  earthy  gray  to  purplish 
slates,  or  locally  phyllites,  with  which  occur  thin  layers  of  buff  to  pink 
dolomite  and  siliceous  limestone.  The  lowest  beds  seen,  which  we  take 
to  be  near  the  base  of  the  series,  are  of  red  and  gray  quartzite  with  local 
layers  of  conglomerate. 

The  Tung-yu  limestone  includes  all  the  upper  part  of  the  Hu-t'o 
system.  The  characteristic  rock  is  gray  limestone,  in  which  chert  is  usually 
present  in  notable  quantity  and  often  in  masses  or  sheets.  The  massive 
beds  of  limestone  vary  in  thickness  from  10  feet  to  500  feet,  3  to  150  meters, 
or  more,  and  strata  of  gray  to  red  slates  or  phyllites  occur  between  them. 
The  sequence  is  very  like  that  of  the  underlying  Tou-ts'un  group,  but  the 
relative  proportions  of  slate  and  limestone  are  reversed.  The  thickness 
of  the  Tung-yu  limestone  is  probably  3,000  feet,  900  meters,  or  more. 

Throughout  northern  China  there  is  a  limestone  formation  which  is 
lithologically  identical  with  the  heavy  beds  of  the  Tung-yii  group,  and 
occupies  the  stratigraphic  position  of  the  whole  Hu't'o  series.  We  regard 
it  as  the  equivalent  of  the  Hu-t'o,  but  have  given  it  the  distinctive  name  of 
Ta-yang  from  a  village  in  Chi'-li  near  which  it  is  well  developed,  longitude 
115°  5o',latitude  38°  45'. 

The  Ta-yang  is  a  dark-gray,  massive  limestone,  which  is  distinguished 
from  the  very  similar  Sinian  limestones  by  abundance  of  chert  and  absence 
of  fossils.  The  formation  is  exceedingly  uniform  in  lithologic  character; 
the  greater  or  less  proportion  of  chert  and  the  occasional  occurrence  of 
white  quartzite  being  the  chief  variations.  A  notable  characteristic  is  found 


*Vol.  i,  p.  136. 

t  Ibid.,  pp.  123-125. 


LATER  PROTEROZOIC.  9 

in  curved  and  minutely  contorted  laminae  of  flint,  the  contortion  of  which 
appears  to  be  independent  of  local  deformation  of  the  strata.  Similar 
bands  have  been  noticed  in  the  Siyeh  limestone  of  the  Belt  formation,  Mon- 
tana.* They  are  noted  by  Loczy  as  occurring  in  the  Nan-shan  sandstone 
of  Tibet. f  Similar  forms,  described  by  Stose  in  Cambrian  limestones 
of  the  Appalachian  Valley,  are  classed  as  Cryptozoan  proliferum  Hall.J 
Whether  the  peculiar  structures  are  in  some  cases  mechanical  or  organic  is 
not  known, but  they  have  a  long  range — from  late  Proterozoic  to  Ordovician. 
They  have  not,  however,  been  seen  in  the  Sinian.  Neither  have  the  oolitic 
and  conglomeratic  phases  of  the  latter  been  observed  in  the  Ta-yang. 

The  thickness  of  the  Ta-yang  in  a  partial  section  measured  by  Black- 
welder  west  of  the  type  locality  exceeded  1,200  feet,  360  meters,  by  an 
unknown  amount.  Willis  observed  a  section  northwest  of  T'ang-hien, 
Chi'-li,  which,  though  interrupted  by  at  least  two  normal  faults,  appeared 
to  include  6,000  feet,  1,800  meters,  of  the  limestone. §  The  thickness  is, 
no  doubt,  several  thousand  feet. 

At  the  base  of  the  Ta-yang  limestone  is  usually  a  thin  stratum  of 
slate  or  phyllite,  which  rests  in  marked  unconformity  upon  the  T'ai-shan 
complex  (Archean).  No  doubt  the  limestone  may  occur  in  unconformity 
on  the  Wu-t'ai  schists,  as  does  its  probable  equivalent,  the  Hu-t'o  system, 
but  we  did  not  observe  any  such  instance.  The  occurrences  we  saw  were 
at  points  west  of  Pau-ting-fu,  Chi'-li,  and  have  been  described  in  detail. || 

A  contact  of  the  Ta-yang  limestone  with  strata  of  Sinian  age  was 
observed  at  Nan-t'ang-me'i,  Chi'-li  (see  vol.  I,  fig.  27,  and  atlas  sheet  F  I). 
A  very  heavy  bed  of  residual  chert  pebbles,  derived  from  the  pre-Cambrian 
limestone  there,  occurs  beneath  quartzite  and  black  argillite,  which  are  con- 
formable to  the  overlying  Sinian  and  which,  though  lithologically  peculiar, 
are  believed  to  belong  to  that  system.  The  body  of  residual  chert  is 
regarded  as  an  accumulation  on  the  eroded  surface  of  the  Ta-yang,  which 
was  therefore  folded  and  exposed  before  the  lowest  Sinian  stratum  was 
deposited. 

Having  thus  described  the  Ta-yang  limestone  and  its  relations  as  we 
saw  them,  I  give  the  following  sections  from  von  Richthofen,  in  which 
he  noted  strata  that  closely  resemble  it  in  character  and  stratigraphic 
position  and  which  we  consider  to  be  its  equivalents.  These  sections  also 
include  the  Sinian,  namely,  von  Richthofen's  Obersinisch,  and  the  Ta- 
yang  equivalents  are  described  by  him  as  the  Untersinisch.  He  did  not 

*  Stratigraphy  and  Structure  of  the  Lewis  and  Livingston  Ranges,  B.  Willis,  Bull.  G.  S.  A.,  vol.  xm, 
p.  305,  1902. 

t  Reise  des  Grafen  Szechenyi  in  Ostasien,  vol.  I,  p.  553. 
JChicago  Journal  of  Geology,  vol.  xiv,  pp.  210  and  217,  1906. 
§Fig.  27,  vol.  i,  page  131. 
II  Vol.  i,  p.  130. 


10 


RESEARCH   IN   CHINA. 


observe  an  unconformity  between  the  two,  but  our  observations  of  other 
sections,  nevertheless,  lead  us  to  infer  that  an  unconformable  relation  is 
general  between  the  Ta-yang  and  the  Sinian  systems. 

Von  Richthofen's  first  section  is  across  the  Nan-k'ou  range,  north- 
west of  Peking,  en  route  to  Kalgan. 

SECTION  IN  THB  NAN-K'OU  RANGE  (VON  RICHTHOFEN).* 


Description  of  the  rocks. 


m  Evenly  bedded  limestones  without  chert , 
dark  gray  to  blackish;  fine-grained; 
break  splintery  and  conchoidal,  some- 
times uneven.  Beds  2  to  12  inches  thick, 
seldom  more,  well  separated  from  one 
another.  Non-fossiliferous.  Here  occur 
the  limestones  with  horizontally  em- 
bedded, flattish,  rounded  bodies  which 
give  worm-like  outlines  in  cross-section. 
The  bodies  here  consist  mostly  of  dense 
black,  the  matrix  of  crystalline  lime- 
stone. These  "Wurmkalke"  are  every- 
where characteristic  of  an  upper  horizon. 
Another  typical  rock  is  greenish  splin- 
tery limestone.  Total  thickness 

1  Globulitic  limestones,  clear  gray  to  black. 
Globulites  mostly  size  of  oat  kernels, 
seldom  as  large  as  peas.  Beds  2  inches 
to  2  feet  thick.  Trilobites  abundant .... 

k   Green  strata 

i  Globulitic  limestones  like  1,  predomin- 
ating, with  dense  homogeneous  lime- 
stones interbedded 

h    5.    Red  clay  shales 120' 

4.   Gray  limestone 80' 

3.    Red  strata 80' 

2.    Dense  siliceous  limestones  of  flat  con- 
choidal fracture,  very  evenly  bed- 
ded;  whitish,  greenish,  reddish; 
prevailingly  greenish-white .  200' 
i .    Red  clay  shales 100' 

g  Gray,  dense  limestone,  in  part  fine- 
grained crystalline 

f  Black  and  gray  sandy  clay  shales  and 
sandy,  in  part  micaceous  slates,  partly 
even,  partly  curved.  (Krummschalig.) 
Yellow  sandstone  with  iron  ore 

e  Whitish-gray,  fine-grained,  crystalline  lime- 
stone, with  interrupted  interbeddingand 
knots  of  black  flint 

d  Blue  crystalline  siliceous  limestone,  in  part 
pure,  in  part  interbedded  with  thick 
l>eds  of  flint.  Thickness  not  determined, 
but  great. 


Thickness 
(feet). 


500 
80 


1500 


580 


400 


500 


2500 


Equivalents  in  terms  of  this  volume. 


The  limestone  (m)  comprises  strata  which 
are  characteristic  of  the  Tsi-nan  and 
Chau-mi-tien  limestones.  The  non-fos- 
siliferous  condition  is  specially  marked  in 
the  former,  but  fossils  are  not  common  in 
the  latter.  The  "Wurmkalke,"  conglom- 
eratic limestones,  are  well  developed  at 
the  base  of  the  Chau-mi-tie'n.  A  distinc- 
tion between  the  two  would  scarcely  be 
recognized  in  reconnaissance.  The  thick- 
ness is  less  than  their  combined  volume, 
but  the  upper  part  of  von  Richthofen's 
section  is  covered. 


Strata  comprised  under  i,  k,  and  1  corre- 
spond to  the  oolitic  limestones  and  green 
shales  of  the  Kiu-lung  group  of  Shan-tung. 
The  thickness  of  oolitic  limestone  is  four 
times  any  measure  which  was  there  seen. 
It  may  be  overestimated,  but  if  correct 
does  not  affect  the  probability  of  close 
correlation. 

Beds  i  to  5  inclusive  (h)  are  very  character- 
istic of  the  Man-t'o  formation  of  Shan- 
tung. The  200-foot  limestone  bed  is 
much  thicker  than  any  occurring  there, 
but  holds  a  stratigraphic  position  like 
that  of  a  thin  layer  in  the  type  section. 


Beds  f  and  g  are  unfamiliar;  they  appear  to 
be  upper  members  of  the  Ta-yang  lime- 
stone, which  were  eroded  in  the  sections 
we  observed. 


Beds  d  and  e  are  typical  Ta-yang  limestone, 
and  in  view  of  the  great  thickness,  the 
lithologic  identity,  and  similar  position 
below  the  Man-t'o,  we  feel  confident  of 
their  being  equivalent  to  that  formation. 


*  China,  vol.  n,  p.  306. 


I,ATER   PROTEROZOIC,    NAN-K'OU   TERRANE.  II 

The  close  comparison  practicable  between  the  observations  which 
von  Richthofen  made  in  rapidly  crossing  the  Nan-k'ou  pass  and  the  detailed 
sections  we  were  able  to  measure  in  Shan-tung  bears  testimony  to  the  accu- 
racy and  painstaking  character  of  his  work.  The  differences  are  not  greater 
than  might  be  expected  in  sections  300  miles  apart,  and  all  the  character- 
istic earmarks  of  the  formations  are  noted  by  him  in  their  appropriate 
succession.  Although  he  was  not  able  to  collect  fossils,  he  observed  their 
occurrence  at  horizons  elsewhere  abundantly  fossiliferous.  That  von  Richt- 
hofen did  not  see  any  unconformity  between  the  Sinian  and  the  strata 
d,  e,  f,  g,  which  we  assign  to  a  pre-Sinian  system,  is  not  surprising.  He 
remarks  that  the  dip  in  the  red  strata  (basal  Sinian)  was  variable.  The 
limestones  are  very  much  alike  in  the  two  systems,  and  even  one  who  is 
looking  for  an  unconformity  may  easily  pass  the  contact  in  crossing  a  single 
section  en  route  to  "distant  night  quarters  which  were  difficult  to  reach." 
Negative  evidence  of  that  kind  has  little  or  no  weight.  Nevertheless,  it 
is  obvious  that  the  strata  in  the  Nan-k'ou  pass  are  less  closely  folded  than 
in  the  vicinity  of  Si-ta-yang,  where  we  observed  the  pre-Sinian  rocks,  and 
it  is  possible  that  an  unconformity  of  dip  may  not  exist.  But  even  if  the 
strata  be  conformable,  it  would  still,  in  our  judgment,  be  undesirable  to 
extend  the  term  Sinian  to  the  great  body  of  siliceous  limestones  below  the 
Man-t'o  shale,  the  first  formation  laid  down  in  consequence  of  the  trans- 
gression with  which  the  Sinian  period  opened. 

If  the  equivalency  of  the  Ta-yang  limestone  with  that  exposed  in  the 
Nan-k'ou  pass  be  eventually  established,  it  will  be  desirable  to  abandon 
the  term  Ta-yang  for  Nan-k'ou  as  the  name  of  the  system.  Nan-k'ou  is 
the  locality  where  the  strata  were  first  distinguished;  they  are  apparently 
more  completely  represented  there.  The  locality  is  at  once  well  known 
and  accessible,  it  being  on  the  highway  from  Peking  to  Kalgan.  Believing 
the  strata  to  be  equivalent,  I  regard  Ta-yang  as  a  local  name  that  in 
systematic  discussion  should  give  way  to  Nan-k'ou.  Cherty  limestones  of 
the  Nan-k'ou  terrane  are  described  by  von  Richthofen  as  outcropping  in 
a  ridge  adjoining  the  Nan-k'ou  range,*  but  the  section  is  incomplete. 

In  southern  Chi-li,  near  "Hwo-lu-hsien,"  longitude  114°  30',  latitude 
38°+,  a  section  of  limestones  is  exposed  in  the  "  Hsi-p'ing-shan "  moun- 
tains bordering  the  Great  Plain,  which  von  Richthofen  describes  as  follows 
from  above  downward: 

Firm  sandstone,  white  and  gray. 
Crystalline  limestone. 

(Interruption.) 

Greenish  gray,  brightly  colored,  ringine.  thin-bedded  siliceous  limestones;  interbedded 
with  various  sorts  of  strata. 


*China,  vol.  n,  p.  343. 


12  RESEARCH   IN   CHINA. 

Globulitic  and  conglomeratic  ("Wurmkalk")  limestones. 
Thin-bedded  limestones,  red  and  green. 
Red  shales. 

(Interruption.) 
Crystalline  limestone  with  nodules  and  layers  of  flint. 

(Interruption.) 

Alternation  of  crystalline,  thin-bedded,  limestone,  including  thin  layers  of  flint,  with 
quartzite,  epidote  rock,  red  sandstone,  etc. 

(Interruption.) 
Gray  crystalline  limestone. 

This  section  does  not  present  sufficient  continuity  to  enable  us  to 
identify  the  several  formations  precisely,  but  the  sequence  of  three  typical 
groups  of  strata,  cherty  limestone,  red  shale,  and  characteristic  Sinian 
limestone,  is  apparent.  The  cherty  limestones  are  evidently  the  same  as 
the  Nan-k'ou  terrane. 

With  reference  to  the  locality  at  which  we  observed  the  Ta-yang  lime- 
stone, the  two  sections  cited  from  von  Richthofen  lie  respectively,  the 
Nan-k'ou  northeast,  distant  about  200  kilometers,  and  the  Hsi-p'ing-shan 
southwest,  80  kilometers.  The  Ta-yang  locality  thus  lies  between  the  two, 
and  all  three  occur  in  the  foothills  that  bound  the  Great  Plain  on  the  west. 
The  greater  part  of  the  Nan-k'ou  system  in  this  northeast-southwest 
trend  is  siliceous  limestone,  which,  from  its  extent  and  unusual  thickness, 
is  obviously  a  marine  deposit. 

Both  von  Richthofen  and  Blackwelder  have  observed  the  older  sedi- 
mentary rocks  of  Liau-tung.  After  describing  the  fundamental  gneiss 
the  former  sums  up  his  observations*  by  enumerating  two  groups,  namely, 
black  quartzites  and  hornblende  schists,  which  are  intruded  by  granites 
and  greenstones  and  weather  down  to  a  rich  soil  and  rolling  landscape; 
and  the  Ta-ku-shan  series,  consisting  of  firm,  well-stratified  quartzites  of 
yellowish  and  whitish  tints,  together  with  clay  schists,  mica  schists,  and 
crystalline  limestone.  The  schists  and  limestone  occur  in  intimate  but 
indeterminate  relations  with  the  quartzites.  The  schists  attain  a  thickness 
of  several  thousand  feet;  the  limestone  is  of  limited  or  local  occurrence 
only.  These  strata  are  intruded  by  the  Korea  granite,  and  unconform- 
ably  overlain  by  a  red  cross-bedded  sandstone  with  occasional  conglomer- 
atic layers,  the  Yung-ning  sandstone. 

According  to  von  Richthofen,  the  Yung-ning  sandstone  belongs  to  his 
"Untersinisch."t  Blackwelder,J  on  the  other  hand,  regards  it  as  a  local 
development  of  the  Man-t'o  shales,  the  red  littoral  deposit  that  marks  the 

*  China,  vol.  n,  p.  106. 

•f  Ibid.,  vol.  it,  pp.  73  and  109. 

J  Research  in  China  vol.  i,  p.  95. 


PROTEROZOIC,   CENTRAL   CHINA.  13 

Sinian  (Cambrian)  transgression;  and  if  that  be  the  case  it  falls  into  von 
Rich thof en's  "Obersinisch." 

In  Shan-tung  von  Richthofen  distinguished  a  metamorphic  series 
which  included  limestone  and  certain  quartzites.  The  two  were  not  seen 
in  contact  and  their  relations  remain  indeterminate  between  themselves 
as  well  as  to  similar  metamorphic  formations  elsewhere.  The  sequence, 
which  includes  crystalline  limestone,  occurs  in  eastern  Shan-tung,  between 
Chef oo  and  Tong-chou-fu,  with  a  thickness  of  several  thousand  feet.  The 
lower  part  is  mica  schist,  which,  higher  in  the  succession,  gives  place  more 
and  more  to  alternating  limestone  beds  which  attain  great  thickness  and 
make  up  the  upper  part  of  the  system  in  the  "Kung-sun-shan."  This  strati- 
graphic  sequence  resembles  that  of  the  lower  Wu-t'ai  series  of  Shan-si,  and 
the  antiquity  of  the  rocks,  as  judged  by  schistosity  and  metamorphism,  is 
similar ;  but  the  series  may  be  of  some  other  Proterozoic  age. 

The  quartzites  occur  near  Ch'ang-kiu-hien,  in  eastern  Shan-tung,  and 
constitute  a  mountain  mass  cut  through  by  diorite.  They  are  much  folded 
in  a  region  where  the  Sinian  is  not,  and  are  of  pre-Sinian  age,  probably 
equivalent  to  the  Ta-ku-shan  quartzites,  according  to  von  Richthofen. 

PRE-SINIAN  ROCKS  OF  CENTRAL  CHINA. 

The  typical  occurrences  of  rocks  of  the  Wu-t'ai  and  Hu-t'o  or  Nan- 
k'ou  systems  are  confined  to  the  eastern  part  of  the  continent.  They  lie 
2°  to  4°  of  longitude  west  of  the  present  eastern  coast,  between  the  parallels 
of  38°  and  40°  north.  In  the  same  latitude  they  are  24°  to  26°  east  of  the 
central  meridian  of  Asia,  which  we  may  take  as  longitude  90°  east.  They 
are  apparently  isolated  areas,  known  only  in  the  mountainous  region  of 
northwestern  China,  and  may  eventually  prove  to  be  provincial  systems, 
which  can  not  be  precisely  correlated  with  terranes  of  other  regions.  A 
similar  condition  exists  in  North  America,  where  rocks  of  Proterozoic  age 
are  known  in  several  widely  separated  districts,  but  they  have  not  been 
more  closely  correlated  than  as  earlier  and  later  Proterozoic.  Nevertheless, 
rocks  having  the  lithologic  characters  of  the  Wu-t'ai  and  Nan-k'ou  strata 
and  holding  a  somewhat  similar  position  between  those  which  are  classed 
as  Archean  and  deposits  which  are  identified  as  Paleozoic,  are  known  else- 
where in  Asia,  and  it  is  desirable  to  place  them  roughly  in  parallelism. 

Our  own  observations  are  limited  to  a  single  section  of  the  Ts'in-ling- 
shan,  Shen-si,  and  the  outcrop  in  the  lower  Yang-tzi'  gorges,  Hu-pei.*  Von 
Richthofen, f  Loczy.f  and  Obrutchov§  are  the  original  observers  upon 

*Vol.  i,  pp.  265  and  313. 

t  China,  vol.  n,  p.  557  et  seq. 

JReise  des  Grafen  Sze'chenyi  in  Ostasien,  vol.  I,  chapters  vn,  vm,  and  rx. 

§  Northern  China  and  the  Nan-shan  (in  Russian). 


14  RESEARCH   IN   CHINA. 

whom  we  must  chiefly  depend.  The  citations  from  Russian  geologists, 
given  by  Suess,*  are  very  valuable. 

I  take  up  the  occurrences  of  rocks  which  may  be  related  to  the  Wu-t'ai 
and  Nan-k'ou  systems,  in  geographical  sequence,  proceeding  from  the 
nearer  to  the  more  remote.  The  typical  terranes  of  the  pre-Sinian  sedi- 
ments in  North  China  are  found  in  the  Wu-t'ai-shan,  longitude  114°+, 
latitude  39°±,  northern  Shan-si,  and  in  the  Nan-k'ou  range,  longitude 
ii6°±,  latitude  41°  ±,  northwestern  Chi'-li.  They  have  been  described  in 
the  preceding  section. 

In  central  and  southern  Shan-si,  quartzites  and  schists  of  typical 
pre-Sinian  character  occur  in  the  mountains  northwest  of  Fon-ch6u-fu, 
longitude  112°,  latitude  37°  +  ,  in  the  Ho-shan,  longitude  112°,  latitude  36° 
to  37°,  and  in  the  Fong-huang-shan,  longitude  110°  to  111°,  latitude  35°. 
They  appear  on  anticlines  or  normal  fault-scarps,  below  Sinian  strata.  Our 
information  regarding  them  is  limited,  however,  to  identification  of  float 
brought  down  by  streams  and  distant  observations  of  their  characteristic 
outcrops  beneath  limestone  scarps,  as  neither  von  Richthofen  nor  any  of  his 
successors  has  seen  them  at  close  range  in  place.  Our  notes  are  given  in 
volume  I,  page  171  et  seq. 

A  great  mountain  chain,  the  Ts'in-ling-shan,  stretches  from  east  to  west 
across  Central  China,  between  the  meridians  of  104°  and  114°  cast,  about 
700  kilometers  southwest  of  the  Wu-t'ai-shan.  This  barrier  range,  which 
is  regarded  as  the  eastern  continuation  of  the  Kwen-lung,  consists  chiefly 
of  Paleozoic  and  Mesozoic  strata.  It  is  the  northern  margin  of  a  geologic 
province  that  is  distinguished  by  metamorphism  of  the  Permo-Mesozoic  and 
older  sediments,  which  in  northern  China  are  unaltered.  In  this  respect 
it  bears  to  that  region  much  the  same  relation  as  that  which  the  Sierra 
Nevada  of  California  has  to  the  Great  Basin  province  of  Nevada  and  Utah. 
Within  this  metamorphic  province  there  occur  quartzites,  phyllites,  and 
even  schists,  which  are  in  fact  of  Sinian  age  or  younger,  but  which  have 
pre-Sinian  aspects.  We  are  therefore  obliged  to  be  cautious  in  making 
correlations  on  a  lithologic  basis. 

The  eastern  end  of  the  Ts'in-ling-shan  is  described  by  von  Richthofen 
under  the  name  Fu-niu-shan,  and  a  northeastern  outlier  of  imposing  alti- 
tude is  the  Sung-shan.  These  heights  are  in  Ho-nan,  south  of  the  Huang-ho, 
longitude  113°  east,  latitude  34°±.  In  describing  the  sections  which  he 
saw  in  the  Fu-niu-shan, f  von  Richthofen  mentions  chloritic  schists  and 
crystalline  limestone ;  less  distinctly  crystalline  and  gray-green  slates 
(Thonschiefer)  and  slaty  quartzites;  and  these  strata,  which  are  steeply 
folded,  are  unconformably  overlain  by  coarse  conglomerate  and  sandstone 

*  Face  de  la  Terre,  vol.  ni. 
tChina,  vol.  n,  pp.  496-497. 


EASTERN   TS'IN-UNG-SHAN.  15 

in  which  coal-beds  occur.  This  is  the  section  in  the  southern  ridge,  the 
Kiu-li-shan.  A  range  which  succeeds  on  the  north  consists  of  crystalline 
limestone,  crystalline  schists,  gneiss,  and  a  large  mass  of  granite.  The 
granite  rises  2,500  to  3,000  feet,  750  to  900  meters,  above  the  narrow  pass; 
it  consists  of  a  ground-mass  of  orthoclase,  greenish  plagioclase,  much  quartz, 
some  brown  mica,  and  sporadic  hornblende  of  medium  texture,  in  which 
occur  crystals  of  bright  flesh-red  orthoclase,  that  have  the  form  of  Carlsbad 
twins  and  attain  a  diameter  of  4  inches. 

The  granite  is  plainly  intrusive  in  the  gneiss,  which  it  traverses  in 
large  dikes.  Quartz  veins  are  also  extensively  developed.  Crystalline 
schists  intruded  by  quartz  porphyry  complete  the  section  of  the  range  on 
the  north.  Oolitic  limestone  of  Sinian  character,  but  which  seemed  to 
be  unfossiliferous,  occurs  in  a  parallel  ridge  a  short  distance  to  the  north 
and  is  unconformably  overlain  by  coal-bearing  sandstones.  The  latter  are 
intruded  by  "greenstones"  and  porphyritic  eruptives.  Von  Richthofen 
maps  the  crystalline  schists  and  associated  rocks  of  the  region  as  "gneiss 
and  crystalline  schists  in  general,"  with  the  color  with  which  he  indicates 
the  pre-Sinian  (Archean)  basement.  The  assignment  to  a  pre-Sinian  age 
is  borne  out  by  the  apparent  relation  between  the  metamorphics  and  the 
unaltered  strata  classed  as  Sinian.  In  the  grouping  which  is  adopted  in 
this  report  the  predominantly  sedimentary  rocks  of  pre-Sinian  age  fall 
into  the  Proterozoic  and  their  lithologic  associations  are  with  the  Wu-t'ai 
system,  or  possibly  with  the  Hu-t'o.  A  qualification  of  this  inference  lies 
in  the  intrusive  character  of  the  granite  and  its  possible  Mesozoic  age.  If 
the  metamorphism  is  the  effect  of  an  episode  of  deformation  with  which 
the  intrusions  are  related,  and  the  granite  is  post-Carboniferous,  then  the 
schists,  quartzites,  and  crystalline  limestones  may  be  Paleozoic.  There 
is,  however,  nothing  to  sustain  this  qualification  except  the  fact  that  post- 
Paleozoic  granites  occur  in  the  Ts'in-ling-shan.  Although  not  in  the 
least  gneissoid,  and  therefore  apparently  young,  the  intrusive  is  in  this 
respect,  as  well  as  in  petrographic  constitution,  identical  with  the  Korea 
granite  of  Shan-tung  and  Liau-tung,  which  von  Richthofen  determined 
to  be  pre-Sinian*  and  with  which  he  compares  it. 

The  Sung-shan  in  Ho-nan,  one  of  China's  five  holy  mountains,  was 
seen  by  von  Richthofen  from  a  distance.  It  is  an  isolated  mass  estimated 
by  him  at  8,000  feet  altitude.  A  principal  peak,  the  Yii-tsai-shan,  exhibits 
the  form  common  to  masses  of  the  coarse  granite,  while  the  main  range 
shows  those  sculptured  from  crystalline  schists.  A  relatively  low  ridge, 
the  "Hsiung-shan,"on  the  south  of  the  Sung-shan,  appeared  to  the  traveler 
to  consist  of  lower  and  upper  Sinian  strata  resting  on  a  base  of  schists. 

*  China,  vol.  n,  p.  83. 


1 6  RESEARCH   IN   CHINA. 

Between  the  meridians  112°  and  109°  east,  Loczy  crossed  the  Ts'in- 
ling-shan  on  the  highway  which  connects  the  valley  of  the  Han  with  that 
of  the  Wei'.  In  ascending  the  "Sie-ho"  (Siau-ho  or  Little  River)  he  noted 
several  sections  of  Paleozoic  strata,  which  were  not  metamorphosed,  rising 
between  basins  of  Mesozoic  deposits.  On  the  north  he  next  observed  graph- 
itic schists,  pyritiferous  quartzite,  and  yellow  dolomite,  which  he  classes  as 
"  submetamorphic  Paleozoic  schists."  The  description  of  them*  corresponds 
closely  with  rocks  which  we  observed  on  the  Han  and  south  of  it,  between 
longitude  108°  30'  and  109°  30'  east,  and  classed  as  Middle  Paleozoic  and 
Carboniferous.  The  observations  thus  agree. 

After  crossing  the  metamorphosed  Paleozoic  strata,  Loczy  came  upon 
a  broad  belt  of  biotitic  schists  of  monotonous  character,  with  which  occur 
dark  amphibole  schists  and  gneiss,  chlorite  gneiss,  and  lenses  of  white 
granular  limestone.  These  metamorphosed  sediments  are  intruded  by 
massive  diorite,  coarse-grained  amphibole  granite,  and  pegmatite,  which 
locally  change  the  schists  to  hard,  fine-grained  gneisses.  He  classes  the 
complex  under  the  Azoic  or  Archean  formations.  They  are  unconform- 
ably  overlain  by  slightly  coherent  conglomerate,  sandstone,  and  shale,  of 
Jurassic  age;  beyond  these  super jacent  beds  reappear  quartzitic  dolomitic 
limestone,  quartzite,  and  gray  micaceous  phyllites  of  the  mctamorphic 
Paleozoic  group;  and  they  are  in  a  short  distance  again  succeeded  by  a 
broad  zone  of  monotonous  mica  schist,  amphibole  schist,  and  gneiss, 
penetrated  by  eruptives.  The  main  range  of  the  Ts'in-ling-shan  is  thus 
reached  and  is  found  to  consist  of  the  supposed  Archean  schists  and  huge 
intrusions  of  granite,  which  extend  to  the  northern  margin. 

This  zone  of  gneiss-granite,  gneiss,  amphibole  schist,  mica  schist, 
phyllite,  and  crystalline  limestones,  intruded  by  massive  coarse-grained 
granite,  corresponds  in  strike  with  the  Fu-niu-shanf  (described  in  a  pre- 
ceding paragraph),  and  the  petrographic  characters  of  the  rocks  are  sim- 
ilar to  those  of  that  range.  The  presumption  is  strong  that  the  area  is 
one  of  pre-Sinian  schists  and  intrusives.  They  have  not,  however,  been 
observed  in  unconformable  relation  beneath  the  Paleozoics,  and  their  pre- 
Sinian  age  can  not  be  considered  established,  in  view  of  the  fact  that  post- 
Paleozoic  metamorphism  and  intrusion  is  general  elsewhere  in  the  region. 
Nevertheless,  the  weight  of  evidence  is  in  favor  of  their  antiquity,  and  if 
it  be  accepted  we  must  regard  the  northeastern  portion  of  the  Ts'in-ling- 
shan  as  consisting  of  Proterozoic  and  Archean  rocks.  As  we  did  not  cross 
any  western  continuation  of  the  ancient  gneisses  and  granites  in  longitude 
108°  30',  the  zone  does  not  extend  westward  along  the  face  of  the  range,  as 

*Reise  des  Grafen  Szechenyi  in  Ostasien,  vol.  i,  p.  448  et  seq. 
If  Ibid.,  vol.  i,  p.  446. 


CENTRAI,  TS'lN-WNG-SHAN.  17 

it  was  supposed  to.  It  apparently  runs  to  a  point  west  of  Si-an-fu,  about 
longitude  109°,  and  is  a  triangular  area  bounded  on  the  southwest  by 
metamorphosed  Paleozoics  and  granites  intruded  into  them. 

The  next  section  toward  the  west,  across  the  Ts'in-ling-shan,  is  that 
observed  by  the  expedition  of  1904-05,  between  Chou-chi-hien  and  Shi- 
ts'uan-hien,  in  longitude  108°  30'  E.  It  lies  not  more  than  65  miles,  100 
kilometers,  west  of  Loczy's  eastern  route  and  80  miles,  125  kilometers,  east 
of  von  Richthofen's. 

In  approaching  the  Ts'in-ling-shan  from  the  Wei'  valley,  in  longitude 
1 08°  15',  from  Chou-chi-hien,  we  expected  to  find  the  front  of  the  range 
composed  of  granite,  as  shown  by  von  Richthofen.  Instead,  the  foothills 
and  northern  slopes  consist  of  green  schists,  prevailingly  chloritic,  in  which 
occur  thin  beds  of  quartzite  and  highly  siliceous  marble.  These  rocks  dip 
toward  the  north  at  their  northern  margin,  but  a  short  distance  south  dip 
steeply  southward.  They  maintain  a  uniform  southern  dip  of  bedding 
and  schistosity  for  5.5  miles  to  their  southern  limit  at  Liu-yue-ho,  where 
they  are  succeeded  by  white  quartzite  and  massive  gray  limestone,  folded 
in  a  syncline.  The  contact  was  not  observed,  but  a  coarse  conglomerate 
of  quartz,  quartzite,  and  granite  pebbles  in  a  reddish  or  dark  purple  matrix 
is  supposed  to  be  the  lowest  stratum  overlying  the  schists.  It  occurred  in 
large  masses  in  a  brook,  which  flowed  along  and  near  the  contact.  These 
occurrences  very  closely  resemble  the  relations  observed  by  von  Richt- 
hofen, who  describes  similar  rocks  in  the  statement  quoted  below.  We 
agree  with  him  entirely  as  to  the  petrographic  likeness  between  the  green 
schists  of  these  sections  and  those  of  the  Wu-t'ai  system  of  Shan-si.  Their 
position  beneath  a  distinct  series,  which  can  not  be  younger  than  Paleozoic 
and  from  which  they  appear  to  be  separated  by  a  marked  unconformity, 
is  that  of  pre-Sinian  terranes. 

Von  Richthofen's  description  of  the  rocks  which  he  assigns  provision- 
ally to  pre-Sinian  series,  can  not  be  better  stated  than  in  his  own  words.* 
After  describing  the  general  aspect  of  the  northern  slope  of  the  Ts'in-ling- 
shan  as  it  rises  from  the  plain  of  the  Wei,  he  says,  with  reference  to  the 
Archean  zone : 

The  first  rock  seen  in  place  near  Yi-monn  is  granite,  in  part  of  medium  grain,  in  part 
very  coarse,  a  mixture  of  red  orthoclasc,  some  white  plagioclase,  quartz,  and  black  mica. 
Here  and  there  occurs  a  thinly  laminated  mica  gneiss,  which  occasionally  goes  over  into 
hornblende  and  chlorite  gneiss.  It  is  everywhere  penetrated  by  granite.  I  saw  no  other 
rocks  during  this  day.  Typical  gneiss  and  typical  eruptive  granite  (with  the  exception  of 
gneiss-granite)  predominate  probably  in  the  entire  width  of  the  northern  zone  of  the  moun- 
tain range,  for  in  the  alluvial  cones  along  the  northern  base,  west  of  Kwei-tschonn,  I  saw 
only  these  rocks,  which  were  there  developed  in  great  variety. 


*  China,  vol.  n,  pp.  563  and  565 


1 8  RESEARCH   IN   CHINA. 

He  describes  the  probable  Wu-t'ai  rocks  thus: 

South  of  Twi-tsze-shang,  gneiss  and  granite  give  way  to  a  series  of  rocks  which  are 
characterized  by  green  color,  and  when  the  component  minerals  are  macroscopically  recog- 
nizable consist  of  abundant  hornblende  or  chlorite,  or  of  both  minerals,  and  exhibit  great 
petrographic  variety.  Predominant  are  rocks  composed  of  reddish  feldspar,  blackish 
green  hornblende,  and  dark  scales  of  chlorite.  The  last  often  occurs  in  irregular,  some- 
times sharply  fringed  spots,  with  hornblende,  which  lie  in  a  ground-mass  composed  essen- 
tially of  feldspar.  The  chlorite  then  occurs  next  to  the  hornblende  in  such  manner  that  one 
is  inclined  to  consider  it  an  alteration  product  of  the  latter.  Dikes  of  granite,  pegmatite, 
and  quartz  are  common,  especially  in  the  northern  zone.  With  reference  to  the  arrange- 
ment of  the  constituents,  as  well  as  with  regard  to  their  distinct  separation,  the  rocks  vary 
greatly.  Occasionally  they  are  massive  without  recognizable  parallel  structure,  and  they 
then  have  in  some  places  the  character  of  serpentine,  the  feldspar  being  subordinate. 
More  often  the  magnesium  minerals  are  arranged  in  parallel  surfaces,  sometimes  only 
partially,  as  is  the  case  with  mica  in  gneiss-granite ;  otherwise,  however,  so  regularly  that 
more  or  less  nearly  perfect  hornblende  and  chlorite  schists  are  produced. 

With  the  first  steps  on  this  formation  I  was  reminded  of  the  Wu-t'ai  schists  of  northern 
Shan-si.  Shortly  there  followed  the  typical  members  of  that  formation,  as  a  very  thick 
sequence  of  green,  partially  schistose  rocks,  in  which  none  of  the  constituent  minerals  are 
macroscopically  recognizable.  The  entire  system  of  schists  has,  as  a  whole  as  well  as  in 
its  members,  the  constant  strike  of  west  12°  north,  east  12°  south.  The  dip  is  uniformly 
south,  mostly  at  an  angle  of  50°  to  70°,  occasionally  less  steep.  *  *  * 

Before  reaching  Tsau-liang-yi  other  rocks  are  seen  in  great  numbers  in  float  from  the 
eastern  ravines.  Predominant  among  them  are  dense,  quartzitic  rocks,  whose  fracture 
planes  gleam  with  innumerable  little  feldspar  crystals.  These  are  probably  altered  clayey 
sandstone.  Therewith  occur  conglomerates  of  rounded  quartz,  in  a  matrix  which  partly 
corresponds  to  the  above-described  rock,  is  partly  purely  quartzitic,  and  has  a  reddish  to 
dark-violet  color.  As  I  was  unable  to  find  these  rocks  in  place  I  can  not  say  whether  they 
correspond  to  the  sandstones  and  conglomerates  which  occur  in  the  lower  part  of  the 
Wu-t'ai  formation  south  of  the  temples  of  Wu-t'ai-shan,  or  whether  they  belong  to  the 
coal-bearing  strata  which  are  presently  to  be  described. 

It  will  be  observed  that  the  pre-Sinian  rocks  are  more  extensively 
developed  in  the  western  section  seen  by  von  Richthofen  than  in  the  one 
observed  by  our  expedition.  We  did  not  find  the  zone  which  is  described 
by  him  as  Archean  gneiss  and  granite,  and  the  belt  of  Wu-t'ai  schists  is 
but  5.5  miles,  9  kilometers,  wide,  whereas  that  in  his  section  is  20  miles,  32 
kilometers,  across.  There  is,  indeed,  little  reason  to  suppose  that  the  two 
occurrences  are  one  and  the  same  zone.  The  strike  in  von  Richthofen's 
section,  east  12°  south,  if  extended,  carries  the  belt  which  he  saw  at  least 
12.5  miles,  20  kilometers,  south  of  that  which  we  observed.  This  direction 
appears  to  be  the  trend  of  axes  in  the  range,  and  it  is  probable  that  there 
are  subparallel  belts  on  distinct  folds.  If  so,  the  eastern  zone,  extended 
northwestward,  lies  beneath  the  Wei'  valley,  and  the  western,  extended 
southeastward,  ends  before  it  reaches  our  route.  We  crossed  an  anticline 
in  Paleozoic  strata  about  in  its  line  of  strike. 


WESTERN  TS'lN-UNG-SHAN.  19 

Loczy,  whose  observations  of  the  eastern  Ts'in-ling-shan  have  already 
been  described,  recrossed  the  range  on  the  borders  of  Tibet,  65  miles,  100 
kilometers,  west  of  von  Rich thof en's  route.  Obrutchov  followed  the  same 
way  southward  from  "Hoj-shien"  to  "Quan-jiion-shien,"  and  returned 
northward  by  a  route  that  diverges  to  the  west  and  leads  over  Min-chou  to 
Lan-chou-fu.  The  two  geologists  agree  in  describing  the  structure  as  that 
of  close  folding,  involving  overturned  folds  and  overthrusts.  They  both 
observed  more  or  less  metamorphosed  Paleozoic  strata,  which  make  up 
the  great  mass  of  the  range,  and  among  which  Silurian,  Devonian,  and 
Carboniferous  horizons  are  distinguished  by  fossils.*  They  also  noted 
metamorphic  schists  of  uncertain  age,  which  are  doubtfully  assigned  to  the 
"Archean"  by  Loczy,  and  by  Obrutchov  are  distinguished  from  the  Paleo- 
zoics  under  the  general  term  of  "metamorphic  schists." 

The  section  in  which  the  "Archean?"  rocks  are  most  prominent  lies 
between  "  Lo-jan-shien  "  (Lo-yan-hien)  and  "  Tschau-tjen  "  (Chau-tien)  in 
longitude  106°  20',  between  latitude  32°  30'  and  33°  30'  north.  It  is  in  the 
strike  of  a  wide  belt  observed  by  von  Richthofen,  45  miles,  70  kilometers, 
further  east,  which  on  the  basis  of  the  general  stratigraphic  sequence  was 
classed  by  him  as  of  Paleozoic  age;  and  80  miles,  125  kilometers,  still 
further  east,  near  Ssi-mou-ti,  we  crossed  gneisses,  schist,  and  marble,  which 
are  intruded  by  large  granite  masses  and  which  we  also  regard  as  meta- 
morphosed Paleozoics.f 

In  the  particular  section  of  the  western  Ts'in-ling-shan  under  discus- 
sion, between  Lo-yan-hien  and  Chau-tien,  Loczy  mentions  the  occurrence 
of  crystalline  schists,  gneiss,  and  phyllite,  and  crystalline  limestone,  which 
lie  in  isoclinal  folds  and  are  intruded  by  large  bodies  of  diorite.  He  dis- 
tinguishes argillites,  chloritic  schists,  and  epidotic  schists,  as  well  as  partly 
metamorphosed  Paleozoic  strata,  from  underlying  gneisses,  with  which  they 
are,  however,  folded.  And  he  cites  occurrences  of  fossiliferous  Devonian 
and  Carboniferous  strata  in  nearby  localities.  The  sections  which  he  has 
drawn  showj  that  the  rocks  which,  on  account  of  petrographic  likeness, 
he  has  classed  together,  occupy  a  variety  of  positions  with  reference  to  those 
whose  age  is  more  surely  established.  The  schists  under  discussion  are 
indicated  by  a  red  tint  and  blue  dashes.  In  section  2,  profile  plate  2, 
north  of  Lo-yan-hien,  they  appear  overlying  less  highly  metamorphosed 
"Wu-t'ai?"  schists  on  one  side  and  "early  Paleozoic  limestone"  on  the 
other,  in  a  syncline;  south  of  Lo-yan-hien,  in  the  "Pej-ho-scha,"  they  under- 
lie "Silurian"  strata  and  rest  upon  granite.  Still  further  south,  beyond 

*Reise  des  Grafen  Szechenyi  in  Ostasien,  vol.  I,  pp.  422-439,  plates  u  and  vi.     La  Face  de  la  Terre, 
Suess,  vol.  in,  pp.  270-271,  fig.  35. 
tVol.  i,  pp.  308-310. 
tReise  des  Grafen  Sze'chenyi,  vol.  I,  pp.  465  and  428,  plate  n. 


20  RESEARCH    IN   CHINA. 

the  broad  zone  of  granite  near  "Jam-pa-quan,"  they  appear  to  be  intruded 
by  granite  dikes,  and  are  folded  in  such  a  way  as  to  constitute  anticlines 
between  which  less  highly  metamorphosed  strata,  assigned  to  the  Paleo- 
zoic, appear  in  synclines. 

From  the  observations  of  Obrutchov,  Loczy,  von  Richthofen,  and 
ourselves,  in  four  parallel  sections  across  the  central  and  western  Ts'in-ling- 
shan,  it  thus  becomes  apparent  that  the  geologic  structure  involves  several 
complex  factors.  There  are  metamorphic  rocks,  some  of  which  are  probably 
pre-Cambrian,  and  among  them  may  be  representatives  of  the  basement 
gneisses  as  well  as  of  the  Proterozoic  metamorphosed  series.  There  are 
other  metamorphic  rocks  of  Paleozoic  and  probably  also  of  early  Mesozoic 
age,  which  vary  in  degree  of  metamorphism  according  to  the  intensity  of 
action  incident  to  local  folding  and  intrusion.  And  there  are  areas  of 
Paleozoic  strata  which  exhibit  little  or  no  effect  of  metamorphism.  These 
various  masses  are  closely  folded,  overturned,  and  overthrust,  producing 
relations  as  complex  as  some  of  Alpine  structure. 

We  may  conclude  that  the  occurrence  of  pre-Sinian  rocks  in  the  western 
Ts'in-ling-shan  is  highly  probable.  Where  such  rocks  are  known  in  the 
central  Ts'in-ling-shan,  they  are  chloritic  schists  with  thin  beds  of  quartz- 
ite  and  marble,  very  closely  resembling  the  strata  of  the  Si-t'ai  group  of 
the  typical  Wu-t'ai  district. 

ANCIENT  METAMORPHIC  ROCKS  BEYOND  CHINA. 

Under  this  heading  I  propose  to  consider  the  relations  of  certain  rocks 
which  are  variously  classified  as  Archean,  Wu-t'ai,  Sinian,  early  Paleozoic, 
and  Silurian,  by  observers  in  Tibet,  Indo-China,  and  India. 

In  Tibet  they  constitute  the  unfossiliferous  pre- Devonian  series  of  the 
great  Nan-shan  mountain  system,  and  have  been  observed  by  L6czy  in 
his  journey  along  the  northern  base  of  the  Nan-shan  range,  from  Lan- 
chou-fu  to  Sti-chou  and  return ;  and  by  Obrutchov  in  his  far  more  extended 
journeys  across  southern  Mongolia  and  back  and  forth  among  the  several 
great  ranges  of  the  Nan-shan. 

Under  the  heading  crystalline  schists,*  Loczy  says: 

The  Archean  complex  of  gneisses,  mica  schists,  and  phyllites  plays  a  subordinate 
r61e  in  those  parts  of  the  middle  Kuen-lung  chain  which  we  traversed.  In  none  of  the 
mountains  which  we  crossed  was  I  able  to  distinguish  a  crystalline  axis. 

He  then  discusses  at  some  length  various  occurrences  of  crystalline 
schists,  having  in  mind  chiefly  their  eccentric  position  in  the  individual 
ranges  in  which  they  occur,  but  gives  little  information  concerning  their 

*Reise  des  Grafen  Sz&henyi,  vol.  I,  p.  642. 


OBRUTCHOV,    NAN-SHAN   RANGE.  21 

geological  relations.  As  constituent  rocks  of  the  Archean  he  repeatedly 
mentions  gneiss,  mica  schists,  amphibole  schists,  crystalline  limestone, 
mica  phyllite,  gneiss-granite,  and  biotite-muscovite  granite. 

Referring  apparently  to  the  same  series  of  ancient  crystalline  rocks, 
Obrutchov  frequently  employs  the  terms  "metamorphic  sandstones  and 
schists."  With  reference  to  the  Barun  Ula  range,*  he  says: 

The  axial  part  of  the  range  is  chiefly  composed  of  red  and  green  Archean  gneisses 
dipping  steeply  inward  on  both  slopes,  that  is,  forming  a  remnant  of  an  ancient  syncline. 

In  various  sections  of  the  different  constituent  ranges  of  the  Nan- 
shan  system  which  he  crossed,  for  example  in  that  of  the  Potanin  range, f 
he  distinguishes  a  group  composed  of  gneisses,  quartzites,  micaceous 
schists,  and  intrusive  granite,  from  semicrystalline  schists,  quartzites,  and 
limestones.  Describing  a  section  across  the  Richthofen  range,  he  says : 

On  the  southern  slope  we  see  a  thick  series  of  supra-Carboniferous  deposits,  forming 
one  of  the  southern  ridges,  the  divide  of  the  range.  They  strike  north-northwest  diago- 
nally across  the  range  and  dip  steeply  inward  on  both  sides.  Below  the  peak  Yang-kou-er 
appear  more  ancient  formations,  namely  gray  sandstones  and  shales,  slightly  metamor- 
phosed, which  I  consider  early  Paleozoic.  They  do  not  closely  resemble  the  ordinary 
metamorphic  sandstone  and  schists  of  the  Nan-shan  and  other  parts  of  central  Asia  where 
I  have  seen  them.  Perhaps  they  are  Silurian,  perhaps  still  older. 

It  is  much  to  be  regretted  that  Obrutchov 's  third  volume,  in  which 
he  proposed  to  interpret  the  notes  published  in  the  two  now  available, 
has  not  appeared.  As  they  stand  the  voluminous  accounts  of  his  observa- 
tions offer  little  more  than  detached  petrographic  descriptions,  from  which 
geologic  relations  can  hardly  be  deduced. 

L,6czy  distinguishes  a  system  which  he  describes  under  the  name 
Nan-shan  sandstone,  and  which,  after  having  studied  von  Richthofen's 
second  volume,  he  referred  provisionally  to  the  Wu-t'ai  and  Sinian  systems, 
but  he  did  so  only  with  the  reservation  that  the  correlation  is  suggested, 
but  not  established,  by  the  likeness  in  lithologic  character  and  degree  of 
metamorphism  exhibited  by  the  rocks  of  the  several  systems.  Regarding 
the  Nan-shan  sandstone,  he  states  that  it  consists  chiefly  of  gray-green 
sandstones  and  clay  slates,  which  are  frequently  traversed  by  distinct 
cleavage  or  schistosity  and  which  are  barren  of  fossils,  except  for  occasional 
indistinct  impressions,  that  may  possibly  be  ascribed  to  fucoids.  From 
the  various  sections  and  descriptions  given  in  his  chapter  on  the  northern 
slope  of  the  Nan-shan  range, t  it  appears  that  the  Nan-shan  sandstone  is 
very  intimately  folded  and  is  intruded  by  large  masses  of  granite. 

*  Central  Asia,  North  China,  and  the  Nan-shan.     Obrutchov,  vol.  n,  p.  79  (in  Russian). 

•\Ibid.,  vol.  II,  p.  115. 

t  Reise  des  Grafen  Szechenyi,  vol.  I,  pp.  532-559. 


22  RESEARCH    IN   CHINA. 

Another  series  described  by  L6czy,  which  belongs  in  this  category,  is 
that  which  he  designates  early  Paleozoic  limestones.  He  says  :* 

At  several  points  in  the  range  of  the  Nan-shan  I  found  light-colored,  d'ense,  half- 
crystalline,  sometimes  siliceous,  dolomitic  limestones.  Everywhere  the  limestones  occur 
in  moderately  thick  strata,  conformably  bedded  with  the  Nan-shan  sandstone,  either  inter- 
bedded  or  in  the  form  of  "Klippen."  In  none  of  these  limestones  could  I  find  fossils,  even 
in  numerous  thin  sections.  The  investigations  of  Dr.  Konrad  Schwager  of  the  material 
sent  to  him  likewise  yielded  a  negative  result.  Lines  which  might  suggest  bivalves,  a 
spheroidal  inclusion  with  a  tangled,  reticulated  character,  and  a  globulitic  structure,  occa- 
sionally suggest  an  organic  origin. 

At  the  time  that  L,6czy  and  Obrutchov  wrote  their  descriptions  they 
could  compare  the  formations  which  they  had  observed  only  with  the 
Archean,  the  Wu-t'ai  or  Huronian,  and  the  Sinian.  According  to  von 
Richthofen's  definition,  the  latter  comprised  strata  conformably  under- 
lying the  Cambrian,  which  might  therefore  be  considered  the  most  ancient 
Paleozoic  deposits.  In  distinguishing  the  Nan-k'ou  or  Hu-t'o  system  as  a 
pre-Cainbrian  series,  separated  from  the  fossiliferous  beds  by  an  uncon- 
formity and  characterized  by  highly  siliceous  limestones  and  slight  meta- 
morphism,  we  have  found  a  series  which  closely  resembles  the  rocks  which 
Ivoczy  designates  early  Paleozoic.  As  the  limestones  to  which  he  thus 
refers  are  interbedded  with  the  Nan-shan  sandstone,  some  part  of  that 
system  is  also  probably  to  be  referred  to  the  Nan-k'ou  (Hu-t'o)  terrane. 

Among  the  more  highly  altered  metamorphic  schists,  quartzites, 
and  crystalline  limestones,  there  may  probably  be  found  the  representa- 
tives of  the  Wu-t'ai  system.  It  would  not  be  surprising  if  outcrops  of 
these  ancient  formations  should  be  found  to  lie  in 'one  or  more  rudely  con- 
centric arcs  corresponding  to  the  strike  of  the  mountain  ranges,  which 
extend  from  the  type  locality,  the  Wu-t'ai-shan  in  northern  Shan-si,  through 
southern  Shan-si  and  across  Shen-si  and  Kan-su  to  the  Nan-shan  in  Tibet. 
This  is  the  outline  of  the  continental  region  during  the  succeeding  Sinian 
age,  and  it  would  be  in  accord  with  the  general  laws  of  relation  between 
continental  structure  and  mountain  trends  that  representatives  of  the 
Wu-t'ai  system  should  be  found  at  intervals  along  this  arc. 

In  his  southward  journey  from  the  northern  Tibetan  regions  where  the 
Nan-shan  sandstone  is  typically  developed,  through  western  Yiin-nan  to 
Burmah,  L,6czy  observed  formations  which  he  correlates  with  it.f  They 
occur  chiefly  between  Ta-tsie"n-lu  and  Ba-t'ang  in  the  outer  ranges  of  the 

*Reise  des  Grafen  Sz£chenyi,  vol.  I,  p.  651. 
\lbid.,  vol.  I,  p.  724. 


ANCIENT  SCHISTS,   INDOCHINA.  23 

Alps  of  eastern  Tibet.  He  describes  the  rocks  as  monotonous  clayey 
sandstone,  of  gray  and  dark  colors,  associated  with  clay  schists  and  also 
with  amphibolite  and  chlorite  schists.  The  presence  of  the  latter  leads 
him  to  correlate  the  series  with  the  Wu-t'ai.  Semicrystalline  limestones 
occur  beneath  the  sandstones,  the  strata  being  extensively  intruded  by 
granite. 

Throughout  much  of  Indo-China  there  occur  ancient  schists  which  are 
described  by  Fuchs  and  Saladin,*  who  distinguish  two  varieties,  the  one 
greenish,  siliceous,  hard,  and  compact,  apparently  the  upper  part  of  the 
terrane;  and  the  other  a  gray,  lustrous  schist.  These  metamorphic  rocks 
are  associated  with  granite,  which,  as  we  may  infer  from  the  language  of 
the  authors,  is  probably  intrusive.  The  petrographic  description  is  suf- 
ficiently close  to  that  of  Loczy  to  suggest  that  these  metamorphic  strata 
correspond  with  the  supposed  Nan-shan  sandstone  occurring  between  the 
Ta-tsien-lu  and  Ba-t'ang,  especially  as  the  mountain  ranges  and  structural 
features  are  continuous.  The  schists  are,  however,  classed  by  Fuchs  and 
Saladin  as  possibly  Silurian  (probably  in  the  sense  of  early  Paleozoic)  as 
they  underlie  fossiliferous  Devonian  schists  and  sandstones;  but  the  strati- 
graphic  relations  have  not  been  worked  out  and  it  is  not  clear  how  old  the 
pre-Devonian  rocks  may  be.  In  a  recent  letter  from  M.  Emm.  de  Mar- 
gerie  my  attention  is  called  to  the  occurrence  of  extensive  and  massive 
conglomerates  which  may  represent  the  lower  Cambrian  or  pre-Cambrian 
glacial  deposits  in  this  region. 

Westward  from  Yiin-nan  and  Burmah  in  the  Himalayas  occur  ancient 
rocks  which  were  described  as  an  older  granite-gneiss  and  a  younger  series 
of  schists  (the  Vaikrita  systemf) .  Haydenf  states  that  the  granite-gneiss 
is  intrusive  in  Cambrian  and  Permian  strata,  and  that  certain  schists 
assigned  to  the  Vaikrita  system  are  altered  Cambrian  slates  and  quartzites. 
In  the  Peninsula  region  of  India  gneisses  have  been  distinguished  as  older 
and  younger,  but  without  sufficient  basis  in  observed  relations,  according 
to  Oldham.§  No  distinctly  sedimentary  pre-Cambrian  rocks  are  known 
there. 

Thus  we  are  not  as  yet  able  definitely  to  distinguish  metamorphic 
Proterozoic  rocks  in  south  China  or  India  in  such  a  way  as  to  draw  a 
parallel  with  the  Wu-t'ai  schists. 

*  Explorations  des  Gttes  de  Combustibles  de  1'Indo-Chine,  Annales  des  Mines,  8  ser.,  M£m.  2,  p.  205. 
fGriesbach:  Geology  of  the  Central  Himalayas,  India  Geological  Survey  Memoirs,  xxm,  p.  40. 
t  Geology  of  Spiti,  India  Geological  Survey  Memoirs,  xxxvi,  pt.  i,  p.  8. 
§  Manual  of  Geology  of  India,  page  23. 


24  RESEARCH    IN   CHINA. 

PRE-S1NIAN  DIASTROPHISM.* 

Diastrophism  is  a  phenomenon  which  finds  expression  in  the  oldest 
rocks  as  well  as  in  the  youngest  mountains  of  all  continents,  and  of  this 
general  fact  Asia  is  the  most  striking  illustration  which  the  earth  presents. 
Large  areas  exhibit  rocks  which  have  been  intensely  deformed  and  are 
among  the  most  ancient  known ;  and  the  greatest  mountain  chains  challenge 
credulity  by  the  evidence  of  their  extreme  youth.  The  earlier  diastrophic 
movements  escape  us  in  the  mists  of  unrecorded  ages  of  earth-history;  we 
take  up  the  observation  only  where  the  facts  become  partly  intelligible; 
but  from  that  remote  time  to  the  present  we  find  a  connected  series  of 
events. 

Suess  describes  these  facts  and  draws  the  conclusion  that: 

The  compressive  force  formerly  acted  throughout  the  entire  expanse  of  the  globe, 
whereas  now  it  is  localized  in  certain  special  regions.")" 

An  alternative  view  may  be  stated:  namely,  the  widely  distributed 
effects  of  schistosity  are  produced  in  masses  that  lie  in  a  relatively  deep- 
seated  zone,  where  movement  is  somewhat  uniformly  distributed ;  whereas, 
special  regions  of  folding  are  peculiar  to  a  relatively  superficial  zone,  in 
which  movement  is  localized  and  concentrated  by  special  conditions  of 
structure  and  resistance.  That  is  to  say,  the  distinction  between  widely' 
'.  distributed  and  localized  structures  is  one  of  depths  rather  than  of  times. 
This  view  is  stated  more  in  detail  in  the  final  chapter  of  this  volume. 
Applying  it  to  the  explanation  of  the  general  structure  of  the  Archean, 
we  may  reason  that  the  masses  which  that  structure  characterizes  were 
deformed  in  a  zone  at  such  a  depth  that  they  were  below  any  localized 
erogenic  effects.  That  there  were  regions  of  special  plication,  even  in  the 
Archean  is  probable,  but  the  superficial  folded  masses  have  been  eroded. 

Gneisses  and  schists  constitute  the  T'ai-shan  complex  of  China  and 
also  the  corresponding  rocks  described  by  many  observers  in  Siberia,  central 
Asia,  India,  and  Indo-China,  and  designated  "older  Archean."  They  are 
everywhere  fundamental  rocks;  their  constitution  is  very  complex;  they 
consist  of  minerals  resulting  from  extreme  metamorphism  under  great 
pressure;  and  their  larger  structure  exhibits  repeated  intrusions,  often 

*Following  Powell  and  Gilbert  (U.  S.  G  S.  Monograph  I,  pp.  3-340)  I  shall  use  the  term  diastrophism 
to  denote  all  the  processes  of  deformation  of  the  earth's  crust,  and  shall  distinguish  between  orogenic  move- 
ments, which  result  in  the  commonly  observed  phenomena  of  mountain  ranges  and  mountain  structure, 
and  epeirogenic  movements,  which  are  expressed  in  the  elevation  or  depression  of  broad  areas  and  are 
recorded  in  eroded  surfaces  or  accumulated  sediments.  The  distinction  is  one  which  has  found  little, 
if  any,  recognition  in  the  literature  relating  to  Asia,  but  which  is  fundamental  and  clearly  recognizable  in 
the  geologic  facts. 

|La  Face  de  la  Terre,  vol.  in,  p.  7. 


OF  THE   ARCHEAN.  25 

along  parallel  planes.  It  is  commonly  recognized  that  they  acquired  these 
characters  when  deeply  buried  beneath  masses,  which  subsequently  were 
eroded  in  consequence  of  exposure  above  sea-level. 

To  pursue  this  thought  would  lead  too  far  afield  in  the  direction  of 
theory.  Adhering  to  the  facts,  we  may  consider  the  leitlinien,  or  axial 
trends,  of  the  Archean  in  Asia  as  developed  by  Suess.*  They  maintain 
two  principal  courses,  the  one  known  as  the  Saian  direction  striking  east- 
southeast  or  southeast;  and  the  other,  the  Baikal  direction,  east-northeast. 
Trends  having  these  bearings  meet  south  of  Irkutsk,  where  they  were  first 
distinguished  by  Tchersky,f  and  there  inclose  on  the  south  the  amphi- 
theater of  Irkutsk.  By  assembling  the  geologic  observations  for  all  northern 
Asia,  Suess  has  traced  these  axial  trends  and  shown  that  they  characterize 
an  immense  area  of  eastern  and  western  Siberia.  The  peripheral  ranges 
extend  from  the  island  of  Sakhalin  across  the  Amur  into  northern  Mongo- 
lia, in  the  Baikal  trend,  and  thence  in  the  Saian  direction  through  the  Saian 
mountains  to  the  Ob.  This  structure  is  not  only  of  vast  extent;  it  is  also 
fundamental,  as  well  through  its  antiquity  as  through  its  nucleal  position. 
About  it  are  arranged  the  other  structures  of  Asia.  They  are  pendant  from 
it,  as  Suess  happily  says,  like  garlands. 

Succeeding  the  Archean,  in  the  sense  given  that  term  in  these  volumes, 
the  next  oldest  rocks  of  which  we  have  definite  knowledge  are  the  Wu-t'ai 
schists  of  northern  Shan-si.  They  are  early  Proterozoic.  They  probably 
are  not  younger  than  many  terranes  classed  as  Archean  in  the  broader 
sense  of  that  term  commonly  employed  by  writers  on  Asiatic  geology,  for 
similar  strata  have  not,  as  a  rule,  been  sharply  distinguished  from  the  basal 
gneisses. 

The  Wu-t'ai  schists  are  distinct  sediments,  which  represent  familiar  \  / 
conditions  of  erosion  in  a  sequence  that  is  generally  recognized  among 
later  deposits.  Unfortunately  our  interpretation  is  in  a  measure  balked 
by  uncertainty  of  the  exact  stratigraphic  succession  and  ignorance  of  the 
former  extent  and  distribution;  but  I  proceed  on  the  basis  of  our  present 
understanding. 

According  to  that,  the  lower  Wu-t'ai  strata  are  heterogeneous,  quartz- 
ose  and  clayey  in  the  lower  part,  more  argillaceous  in  the  middle,  calcare- 
ous above;  and  this  lower  series  is  unconformably  succeeded  by  a  great 
thickness  of  shale  which  carries  a  basal  conglomerate  of  large  quartz  and 
quartzite  pebbles.  Regarded  as  products  of  erosion  the  strata  have  a 
perfectly  normal  sequence,  which  corresponds  to  a  complete  erosion  cycle 

*La  Face  de  la  Terre,  vol.  in,  chapter  HI,  Le  Fatte  Primitif.     Summary  on  page  138. 
fl.  D.  Tchersky.     Sur  la  tectonique  des  montagnes  de  la  Siberie  Orientale.  Trav.  Soc.  des  Natura- 
listes,  St.  Petersburg,  xvn,  No.  2,  1886.     Proces-verb.  pp.  52-58. 


26  RESEARCH  IN  CHINA. 

and  subsequent  prolonged  continental  phase,  or  marine  transgression.  The 
latter  is  more  probable,  but  we  can  not  on  present  evidence  exclude  the 
possibility  that  the  upper  Wu-t'ai  strata  accumulated  subaerially  on  a  low- 
lying  land.  Confining  our  attention  for  the  moment  to  the  lower  series, 
which  ranges  from  quartzose  argillaceous  to  calcareous,  we  recognize  a  suc- 
cession of  rocks  which,  though  much  older,  resemble  the  Sinian  (Cambro- 
Ordovician)  terrane.  At  the  base  are  the  weathered,  oxidized  products  of 
subaerial  rock  decay,  such  as,  in  consequence  of  exposure  above  the  plane 
of  gradation,  are  transported  by  streams  and  delivered  to  the  sea.  Toward 
the  top  are  the  finer,  finally  chiefly  calcareous  sediments,  which  result  from 
the  topographic  and  climatic  conditions  that  follow  from  prolonged  fixed 
relations  of  land  and  sea.  The  unconformity  indicates  an  interruption  of 
those  relations  which,  if  the  overlap  of  the  next  later  strata  on  the  Archean 
be  as  great  as  we  suppose,  was  a.  very  notable  interruption.  The  upper 
series  represents  ultimately  renewed  erosion,  transportation,  and  deposition. 
The  Wu-t'ai  deposits  are  several  thousand  feet  thick.  They  are  at  least 
equal  to  the  Cambro-Ordovician  in  duration  of  time  and  altogether  may 
equal  most  of  the  Paleozoic.  The  nature  and  volume  and  sequence  of 
sediments  correspond  with  those  which  represent  epeirogenic  movements 
and  static  conditions  of  later  periods;  they  evidently  indicate  equivalent 
movements  and  conditions  for  those  early  times. 

The  Wu-t'ai  strata  were  folded  and  intruded  by  igneous  rocks,  and  the 
whole  mass  was  rendered  schistose  before  the  next  succeeding  formation 
was  laid  down  in  the  typical  district.  The  igneous  rocks  became  gneisses; 
i  the  heterogeneous  strata  became  biotite,  muscovite,  and  chlorite  schists; 
and  the  limestones  changed  to  marbles,  with  the  development  of  garnet, 
staurolite,  and  other  minerals  from  the  shaly  beds.  Metamorphism  was 
preceded  by  or  associated  with  folding  and  thrusting  into  isoclinal  struc- 
tures. The  phenomena  compare  in  intensity  and  volume  of  rocks  affected 
with  the  effects  shown  by  the  Paleozoics  of  the  Han  region,  China,  or  of 
the  Sierra  Nevada,  California,  as  a  result  of  deformation  during  the  Permo- 
Mesozoic. 

Thus  we  see  that  the  Wu-t'ai  region  passed  through  an  epoch  of  intense 
orogenic  activity  at  the  close  of  the  Wu-t'ai  period  of  the  Proterozoic  era. 

In  other  districts  than  that  of  the  Wu-t'ai-shan,  Shan-si,  where  strata 
are  identified  by  lithologic  character  as  being  probably  of  Wu-t'ai  age,  the 
structural  facts  are  less  well  known.  In  the  Ts'in-ling-shan,  Shen-si,  chlo- 
ritic  schists  with  some  limestone  and  quartzite  occur  unconformably  beneath 
Paleozoic  strata,  from  which  they  are  markedly  distinguished  by  greater 
metamorphism.  The  suggested  events  of  deposition  and  orogenic  disturb- 
ance are  comparable  in  time  and  character  with  those  of  the  typical  region. 


ANTIQUITY   OF   MOUNTAIN   SITES.  27 

Regarding  the  great  Kuen-lung  system  of  Central  Asia,  the  available 
data  clearly  distinguish  highly  metamorphosed  sediments  beneath  Devonian 
or  pre-Devonian  strata.  They  appear  to  fall  into  two  groups,  of  which  one 
consists  of  schists  like  the  Wu-t'ai  schists,  rocks  of  the  other  group  being 
less  altered ;  and  the  facts  indicate  a  sequence  of  activities  which  resemble 
those  of  Wu-t'ai  time. 

Thus  in  an  arc  which  extends  from  the  Wu-t'ai-shan  in  Shan-si  around 
the  southeastern  and  southern  margins  of  the  Mongolian  plateau,  there 
may  be  traced  evidence  of  a  very  ancient  mountain  movement  or  group  of 
movements.  The  axial  trends  of  the  early  structures  correspond  in  a 
degree,  though  not  exactly,  with  the  existing  ranges,  and  this  coincidence 
forms  a  reasonable  basis  for  the  view  that  certain  conditions,  possibly 
mechanical,  have  controlled  and  still  control  the  courses  of  mountain 
chains.  The  coincidence  does  not  demonstrate  the  continued  existence 
of  the  Wu-t'ai  or  Kuen-lung  ranges  as  mountainous  elevations  from  early 
Proterozoic  time  to  the  present;  in  view  of  the  stratigraphic  evidence  that 
Sinian  lands  were  low,  or  of  the  physiographic  evidence  that  the  present 
mountains  have  grown  up  largely  since  the  Tertiary,  such  a  hypothesis  is 
untenable.  Nevertheless,  it  is  one  which  was  commonly  accepted  thirty 
or  forty  years  ago.  Von  Richthofen  regarded  the  Kuen-lung  line  as  a  great 
divide  established  in  a  very  early  period,*  and  describes  the  Ho-shanf  as 
a  monument  of  the  oldest  time,  which  formed  a  long  island  in  the  Carbonif- 
erous sea.  King's  views  of  the  antiquity  of  mountain  heights  of  the  United 
States  are  clearly  expressed  in  the  volume  on  the  systematic  geology  of 
the  Fortieth  Parallel.  The  effectiveness  of  erosion  and  the  significance  of 
strata  as  records  of  highland  or  lowland  conditions  have  since  received 
more  adequate  recognition.  Beginning  with  Powell's  conception  of  a  base- 
level  and  the  demonstration  that  the  Appalachian  folds  had  been  planed, J 
the  generalization  has  been  developed  that  existing  heights  are  nearly  all 
post-Cretaceous  and  largely  post-Miocene.  But  at  the  same  time  the  view 
has  been  strengthened  that  zones  of  mountain  growth  are  so  conditioned 
that  repeated  elevations  occur  on  the  same  sites  with  similar  trends,  though 
at  widely  separated  intervals.  In  the  latter  sense  the  Wu-t'ai  and  Kuen- 
lung  axes  of  mountain  growth  are  very  ancient,  one  may  say  primeval, 
features  of  Asia. 

Traces  of  the  mid-Proterozoic  epoch  of  orogeny  are  found  in  Liau-tung 
and  Shan-tung,  the  eastern  mountain  provinces,  in  meager  occurrences  of 
pre-Sinian  sediments,  which  are  so  metamorphosed  as  to  be  compared  to  the 

*  China,  vol.  u,  pp.  647-648  and  709. 

1  Ibid.,  p.  457. 

|W.  M.  Davis,  Rivers  and  Valleys  of  Pennsylvania,  Nat.  Geog.  Mag.,  vol.  I,  p.  183,  1889. 


28  RESEARCH   IN  CHINA. 

Wu-t'ai  schists.  Von  Richthofen  enumerates  them*  and  nothing  has  been 
added  to  his  account  except  Blackwelder's  notes  on  the  Ta-ku-shan  quartz  - 
ites.  The  facts  do  not  suffice  to  fix  any  dates  other  than  that  one  which 
preceded  late  Proterozoic.  In  the  great  lapse  of  earlier  time  there  were  in 
North  America,  and  probably  also  in  Asia,  several  cycles  of  erosion,  sedi- 
mentation, and  orogeny,  and  the  correlation  on  lithologic  likeness  is  incon- 
clusive. We  believe  the  Wu-t'ai  terranes  to  be  divided  by  an  unconformity, 
and  similar  divisions  probably  exist  elsewhere.  Hence  we  can  not  establish 
equivalency  of  the  epoch  of  folding  in  Shan-tung  with  that  which  was  so 
decided  in  the  Wu-t'ai,  but  in  view  of  the  intensity  of  effects  in  both  regions, 
a  rough  correlation  has  a  presumption  in  its  favor. 

The  orogenic  activity,  which  affected  the  Wu-t'ai  rocks  before  any 
later  beds  known  to  us  accumulated,  divides  the  Proterozoic  of  China  into 
two  major  periods.  The  earlier,  the  Wu-t'ai,  links  itself  to  the  much 
older  Archean;  the  later,  the  Hu-t'o  or  Nan-k'ou  period,  is  like  the  early 
Paleozoic  in  general  character.  Whatever  elevations  resulted  during  the 
dividing  epoch  of  orogenic  activity,  they  did  not  survive  to  deliver  sedi- 
ments to  the  Nan-k'ou  seas.  Except  that  they  may  be  represented  by 
rocks  which  are  not  yet  separated  from  the  late  Proterozoic,  we  must  sup- 
pose that  the  mid-Proterozoics  were  deposited  beyond  the  confines  of  the 
continent  or  in  the  deep  synclinoria  which  in  pre-Tertiary  time  traversed  it. 

Strata  of  the  Hu-t'o  system  in  the  typical  district  succeed  the  Wu-t'ai 
after  an  interval  represented  by  the  profound  orogenic  activity  described 
in  the  preceding  paragraph.  The  sequence  of  sediments  ranges  from 
elastics  of  rather  fine  grain  to  carbonates;  quartzites  interbedded  with 
greater  thicknesses  of  slates  pass  by  transition  upward  into  cherty  lime- 
stones. The  total  thickness  is  very  roughly  guessed  at  5,000  feet,  1,500 
meters.  The  elastics  are  terrigenous  deposits,  probably  of  the  littoral 
zone.  The  equivalent  marine  formations  are  the  lower  limestones  of  the 
Nan-k'ou  formation,  of  which  the  upper  part  is  probably  identical  with 
the  limestone  of  the  Hu-t'o  system.  The  unconformity  and  succeeding 
strata  mark  a  transgression  upon  a  flat  land,  which  was  sufficiently  warped 
to  deliver  to  the  coastal  waters  the  sands  and  clays  of  residual  and  alluvial 
deposits.  Off  shore,  at  a  distance  of  50  miles,  80  kilometers,  or  less,  lime- 
stone formed  from  the  very  inception  of  the  transgression,  and  extended 
landward  as  the  sea  widened.  Such  is  the  record  for  North  China.  If  we 
rightly  correlate  the  Nan-shan  sandstone,  or  that  part  of  it  which  carries 
the  "early  Paleozoic"  limestones  of  Loczy,  with  the  Hu-t'o  system,  the 
evidence  of  similar  shore  conditions  may  be  traced  westward  across  Tibet. 

*  China,  vol.  11,  p.  707. 


CLOSE  OF  THE  PROTEROZOIC.  29 

Late  Proterozoic  strata  are  not  known  in  Shan-tung,  which  seems 
to  have  formed  an  eastern  shore  of  the  strait  in  which  the  Nan-k'ou  lime- 
stone was  deposited.  Nor  have  they  been  noted  elsewhere  in  Asia  outside 
of  Tibet,  unless  some  of  the  rocks  of  western  Yiin-nan,  which  Loczy  assigned 
to  the  Nan-shan  terrane,  prove  to  be  of  that  age. 

In  their  typical  occurrence  in  northern  Shan-si,  Hu-t'o  strata  are  dis- 
cordantly overlain  by  the  earliest  Sinian  (Cambrian)  sediments.  The  older 
rocks  were  evidently  folded  and  eroded  to  a  peneplain,  over  which  the 
Sinian  sea  transgressed.  Where  we  observed  the  Sinian  in  relation  to  the 
Nan-k'ou  limestone  (at  Nan-t'ang-mei',  Chi-li)  an  unconformity  is  indicated 
by  a  basal  conglomerate  of  chert.*  A  discordance  of  dip  was  not  observed, 
but  probably  exists;  yet  the  strata  may  be  parallel.  There  are  no  other 
observations  which  enable  us  to  determine  the  area  affected  by  the  post- 
Nan-k'ou  pre-Sinian  disturbance.  The  effects  may  be  looked  for  through- 
out that  littoral  zone  in  which  the  type  locality  lies  and  which  probably 
extends  along  the  Kuen-lung  system.  The  movement  did  not  compare  in 
intensity  with  that  which  closed  the  Wu-t'ai  period;  and  even  though  it 
should  ultimately  be  found  to  have  affected  an  extensive  belt,  we  can  not 
assign  to  the  epoch  of  deformation  and  consequent  erosion  a  duration  at 
all  equivalent  to  that  of  mid-Proterozoic  diastrophism.  Nevertheless, 
it  appears  to  mark  a  break  in  continental  history  equivalent  to  that  at  the 
base  of  the  Cambrian  in  North  America,  and  consequently  to  be  properly 
regarded  as  the  last  episode  of  the  pre-Cambrian,  immediately  antedating 
the  Sinian  transgression  and  the  advent  of  that  Lower  Cambrian  fauna 
which  is  abundantly  preserved  in  the  Sinian  deposits.  The  limitation  of 
the  term  Sinian  to  a  Cambro-Ordovician  system  is  discussed  in  the  next 
chapter. 

Our  present  knowledge  of  pre-Cambrian  diastrophism  in  eastern  Asia 
may  be  summed  up  as  follows :  During  very  early  times  movements  which 
are  expressed  in  schistosity  and  metamorphism  of  the  most  ancient  rocks 
occurred  in  a  deep-seated  zone.  The  superficial  effects  of  the  compressive 
movements  are  lost;  that  is,  the  fractured  and  simply  folded  rocks  of  that 
early  time  were  eroded  and  the  schists  were  exposed.  The  wide-spread 
occurrence  of  the  Archean  schists  shows  that  epeirogenic  movements  were 
general.  Of  localized  erogenic  phenomena  we  have  no  direct  evidence, 
yet  we  can  not  doubt  that  they  also  developed  in  a  commensurate  scale. 
The  axial  trends  of  Archean  rocks  are  north-northeast  (the  Baikal  direc- 
tion) and  west-northwest  (the  Saian  bearing).  These  meet  south  of  the 
amphitheater  of  Irkutsk,  and  further  south  are  connected  by  the  trends 
which  correspond  with  the  Altai  ranges  of  northern  Mongolia. 

*  Vol.  I  of  this  report,  p.  131. 


3O  RESEARCH   IN  CHINA. 

During  the  early  Proterozoic  a  synclinorium  developed  on  the  site  of 
the  present  Wu-t'ai-shan  of  northern  Shan-si,  and  in  it  were  deposited 
sediments  which  correspond  in  sequence  with  the  progress  of  a  cycle  of 
erosion  from  youth  to  old  age  and  subsequent  marine  transgression.  These 
sediments  were  probably  common  to  a  zone  which  extends  from  the  type 
locality  northeast  and  southwest;  in  the  latter  direction  it  enters  the 
Ts'in-ling-shan  and  thence  curves  west  to  northwest  across  Tibet  in  the 
Kuen-lung  system.  The  corresponding  diastrophic  movements  were  epei- 
rogenic,  and  they  passed  into  a  phase  of  quiescence  such  as  has  since 
repeatedly  characterized  such  movements.  It  is  probable  that  there  was 
more  than  one  epoch  of  erosion,  at  least  one  unconformity  being  recognized 
in  the  sedimentary  series. 

At  a  period  which  may  be  described  as  mid-Pro terozoic,  the  zone  of 
early  Proterozoic  sediments  was  sharply  and  intensely  deformed.  The 
disturbance  was  apparently  accompanied  by  granitic  intrusions  of  large 
volume,  which  were  then  or  afterward  rendered  schistose  in  common  with 
the  folded  strata.  The  events  were  complex.  The  movements  may  be 
classed  as  orogenic,  since  they  resulted  in  deformation  of  strata  by  folding 
and  thrusting  in  an  apparently  well-defined  zone.  The  strikes  follow  the 
Baikal  direction,  northeast-southwest  in  North  China,  change  in  the 
Ts'in-ling-shan  to  east-west  and  northwest,  and  extend  to  the  Kuen-lung. 
They  thus  form  an  arc  outside  that  of  the  Baikal-Saian  curve,  embrac- 
ing Mongolia,  as  was  perceived  by  von  Richthofen*  and  has  been  brought 
out  by  Suessf  and  others.  This  period  of  orogeny  was  for  the  provinces 
affected  equally  as  important,  apparently,  as  the  intense  orogenic  disturb- 
ances which  mark  the  Permo-Mesozoic  period  in  Central  Asia  and  the 
western  United  States.  It  was  very  possibly  an  incident  of  a  period  of 
diastrophic  activity  such  as  closed  the  Paleozoic. 

After  a  period  of  erosion,  during  which  the  altitudes  that  had  resulted 
from  the  preceding  activity  were  materially  or  completely  reduced,  but  of 
which  no  sedimentary  record  is  known,  there  followed  a  cycle  characterized 
by  the  deposition  of  littoral  sediments  in  the  typical  district  of  the  Wu-t'ai- 
shan,  and  of  marine  limestones  in  a  trough  which  traversed  eastern  China. 
Strata,  which  may  be  equivalent,  occur  in  the  Nan-shan  range  of  northern 
Tibet.  The  deposits  again  correspond  with  the  phases  of  an  erosion  cycle 
from  youth  to  old  age,  and  finally  represent  a  transgression  over  a  low 
continent . 

The  last  event  of  the  Proterozoic  (pre-Sinian)  era  was  a  movement 
which  is  recorded  in  folding  of  the  latest  pre-Cambrian  sediments ;  although 
possibly  a  local  phenomenon  of  the  littoral  zone,  so  far  as  is  yet  known,  it 

*China,  vol.  n,  pp.  635  el  seq.,  647. 
t  Face  de  la  Terre,  vol.  HI. 


THE   PLAIN  OP  TRANSGRESSION.  31 

occasions  a  decided  unconformity  of  structure  in  the  Wu-t'ai  district  and 
is  represented  by  an  erosion  interval,  even  where  there  is  no  known  dis- 
cordance of  dip  with  the  Sinian.  It  is  consequently  regarded  as  an  interval 
of  sufficient  importance  to  distinguish  the  Hu-t'o  or  Nan-k'ou  system  of  the 
Proterozoic  era  from  the  Sinian  system  of  the  Paleozoic  era. 

PRE-SINIAN  UNCONFORMITY. 

The  unconformity  at  the  base  of  the  Sinian  system  divides  the  Paleo- 
zoic from  the  pre-Cambrian.  It  is  a  break  of  the  first  magnitude,  corre- 
sponding to  a  period  of  deformation  and  erosion,  even  where  the  underlying 
strata  are  the  Ta-yang  (Nan-k'ou)  limestone  of  the  late  Proterozoic.  More 
commonly  the  subjacent  rocks  are  Archean  and  the  hiatus  embraces  the 
much  longer  times  which  are  in  some  localities  represented  by  the  two 
Proterozoic  systems  of  strata  and  the  sum  of  deformations  and  erosions 
they  have  undergone. 

The  latest  cycle  of  erosion  with  which  the  Proterozoic  closed  was  very 
complete.  The  land  surface  was  reduced  to  a  nearly  perfect  plain,  upon 
which  the  transgressing  sea  of  Sinian  time  found  few  eminences  to  level.  In 
this  statement  we  agree  with  von  Richthofen  as  regards  the  completeness 
of  planation,  but  differ  from  him  in  assigning  to  erosion  the  greater  part 
of  the  work  accomplished.  In  accordance  with  the  prevailing  views  of  the 
time  in  which  he  wrote  his  second  volume  of  China,  he  therein  held  that  the 
major  work  of  denudation  was  due  to  marine  abrasion.  He  says: 

The  first  great  occurrence  after  the  episode  of  folding  was  an  extensive  abrasion,  by 
far  the  most  important  which  is  to  be  demonstrated  in  the  geological  history  of  China. 
The  complete  difference  between  the  tectonic  movements  which  occurred  before  and  after 
the  period  marked  by  this  boundary  suffices  to  show  that  a  very  long  time  interval  lay 
between  the  happenings  of  the  fifth  and  seventh  phase,  since  a  portion  of  the  earth's  crust 
which  previously  had  been  capable  of  intense  internal  movement  was  so  stiffened  that  it 
thereafter  only  changed  its  level  as  a  whole ;  but  we  obtain  a  more  definite  idea  of  the  great 
length  of  this  sixth  period  when  we  consider  that  enormous  mountain  masses  which  covered 
continental  areas  were  completely  swept  away.  From  the  fact  that  formations  whose 
thickness  can  be  measured  only  by  tens  of  thousands  of  feet  occur  in  single  troughs,  we  are 
obliged  to  draw  the  conclusion  that  these  are  relatively  small  roots  of  former  folded  moun- 
tain chains,  which  attained  at  least  the  height  of  the  Alps,  but  then  almost  completely 
vanished.  We  have  repeatedly  referred  to  the  breakers  of  an  advancing  sea,  which  trans- 
gressed over  the  land  in  consequence  of  simultaneous  mechanical  erosion  and  positive  sub- 
sidence, as  the  one  agent  which  is  able  to  produce  a  level  surface  where  there  previously 
existed  an  extensive  mountain  range.  However  much  assistance  may  be  given  by  atmos- 
pheric influences  and  the  running  water  of  the  mainland,  this  alone  is  competent  to  produce 
an  almost  even  surface  of  great  extent.  That  force  is  the  only  one  which  we  may  here 
postulate.  The  surf  removed  not  only  the  folded  masses  of  the  ancient  formations,  but 
also  attacked  their  foundation,  the  old  gneiss,  and  developed  a  plane  of  abrasion  which  ex- 
tends across  the  remaining  portions  of  the  gneiss  as  well  as  over  the  synclines  of  the  younger 


32  RESEARCH   IN   CHINA. 

Archean  strata  and  the  Korea  granite,  as  is  clearly  proven  by  the  uniform  occurrence  of 
the  wide-spread  covering  of  Sinian  sediments.  The  surface  was  not,  however,  perfectly 
uniform,  as  the  eroding  force  could  not  overcome  the  resistance  of  the  hardest  rock.  The 
quartzites  stand  up  in  high  reefs,  as  we  have  seen  in  Liau-tung  at  Sai-ma-ki  a-nd  Ta-ku-shan. 
The  Korea  granite  stands  out  occasionally  in  steep  high  bluffs,  and  yet  in  the  immediate 
vicinity  it  occurs  as  the  surface  of  a  plain  of  abrasion  on  which  Sinian  strata  lie  in  horizontal 
and  undisturbed  position.  The  irregularity  of  the  action  appears  especially  about  the  hard 
cores  of  gneiss  in  the  mountains.  We  have  seen  how  the  layers  of  the  principal  mass  of 
gneiss,  which,  around  the  Yellow  Sea,  strike  north-northwest  south-southeast  and  dip 
steeply,  were  involved  in  the  thrust  in  the  Sinian  direction  and  thrown  into  disturbed 
positions  which  probably  facilitated  erosion,  while  near  these  deeply  eroded  and  decom- 
posed masses  wild  ridges  of  unweathered  gneiss  stand  up.  We  must  consider  them  the 
massive  cores  which  were  not  destroyed  by  the  surf.  They  form  the  characteristic  moun- 
tains of  eastern  Shan-tung  and  Liau-tung.* 

The  view  that  notable  elevations  were  cut  away  by  the  waves  is  not 
tenable  in  contradiction  of  the  evidence  of  Sinian  sediments.  Where  waves 
do  attack  bold  coasts  of  gneiss,  granite,  schists,  and  quartzite,  they  spread 
coarse  deposits  of  the  obdurate  rocks.  Where  large  masses  are  rapidly 
leveled  by  subaerial  erosion  or  marine  abrasion,  sediments  of  corresponding 
volume  gather  in  some  adjacent  basin.  The  Sinian  deposits  do  not  repre- 
sent either  of  these  conditions.  They  are  neither  coarse  nor  voluminous. 
They  are  frequently  fine-grained  calcareous  shale  or  thin-bedded  limestone 
at  the  very  base.  The  mechanical  sediment  of  the  basal  formation  has  the 
character  of  a  fine  alluvium  and  is  of  uniformly  moderate  thickness,  350  to 
500  feet,  105  to  150  meters.  The  material  is  red  soil,  particles  of  ferrugi- 
nous clay  being  thoroughly  oxidized  and  grains  of  sand  coated  with  ferric 
oxide.  The  plane  of  contact  at  the  base  is  sharply  defined,  usually  very 
even,  not  broken  by  abrupt  hollows  or  decided  projections,  but  swelling 
gently  over  rounded  bosses  of  the  harder  rocks.  Pebbles  of  the  subjacent 
rocks  are  wanting  in  the  basal  deposits,  as  a  rule,  and  where  they  occur  are 
limited  to  very  local  accumulations.  Beds  of  arkose  have  not  been  seen,  nor 
even  beds  of  clean  sand  such  as  waves  usually  spread.  Thus  none  of  the 
effects  of  violent  breakers  are  present;  the  evidence  is  that  a  gentler  agent 
cleaned  the  surface  of  the  ancient  rocks.  The  facts  support  the  view  that 
the  lowest  strata  of  the  Man-t'o  formation  were  laid  down  in  the  shallows, 
lagoons,  and  flood-plains  of  a  very  low,  flat  coast,  where  weak  waves,  feeble 
shore  currents,  and  rivers  interacted. 

The  smooth  surface  of  the  old  rocks  is  one  which  has  been  swept  clean, 
as  by  the  wash  of  little  waves  or  by  the  wear  of  a  stream  engaged  in  lateral 
corrasion.  It  is  probable  that  a  layer  of  saprolite  was  removed  in  the 
process.  The  material  laid  down  on  the  bared  rocks  is  usually  mud,  occa- 

*China,  "vol.  n,  pp.  710^711. 


GENERAL   PLANATION.  33 

sioually  mingled  with  coarser  stuff.  In  the  special  case  of  the  Yung-ning 
sandstone  of  Liau-tung,  it  is  cross-bedded  like  a  stream  deposit  from  swift 
and  variable  currents;  usually  it  is  evenly  stratified  after  the  manner  of 
deposits  from  quiet  waters  or  on  flood-plains.  It  is  barren  of  fossils  up  to 
100  feet,  30  meters,  above  the  base,  but  above  that  horizon  marine  forms 
are  evident. 

Hence  it  is  reasonable  to  infer  that  the  zone  of  unconformity,  compris- 
ing the  immediately  subjacent  rocks,  the  contact,  and  the  directly  super- 
jacent  strata,  represents  a  coastal  plain  reduced  through  erosion  and  lateral 
corrasion  by  streams  to  an  even  surface;  covered  during  an  early  stage  of 
subsidence  relatively  to  sea-level  by  alluvium,  and  buried  beneath  fine,  ill- 
assorted  shore  deposits  of  a  shallow,  rippling,  advancing  sea.  Where  the 
waves  removed  the  alluvium  the  marine  strata  are  among  the  lowest; 
where  they  did  not,  the  bottom  layers  are  of  fluviatile  origin. 

It  is  possible  that  such  a  coastal  plain  should  be  diversified  by  an 
occasional  hill  of  resistant  rock,  and  hills  of  that  kind  may  still  survive  if 
preserved  through  burial  in  sediment.  Where  the  strata  have  in  a  recent 
geologic  epoch  been  eroded  from  about  them,  they  may  again  appear  as 
prominent  features  of  the  landscape.  Such  was  von  Richthofen's  view 
regarding  the  quartzite  ridge  of  Ta-ku-shan  and  others  like  it.  While  grant- 
ing the  possibility  of  individual  cases  occurring,  we  do  not  agree  to  the 
statement  of  the  final  sentence  in  the  preceding  quotation :  "They  constitute 
the  characteristic  mountains  of  Shan-tung  and  Liau-tung."  We  consider 
the  present  relief  of  those  peninsulas  to  be  a  relatively  very  modern  phenom- 
enon, and  hold  that  resurrected  hills  of  the  early  Sinian  epoch  are  few.  No 
case  of  the  sort  came  under  our  observation. 

The  preceding  statements  apply  to  the  unconformity  at  the  base  of 
the  Sinian,  wherever  we  saw  it:  in  Shan-tung,  Liau-tung,  Shan-si,  and 
Hu-pe'i.  Its  character  as  a  plane  is  uniform  over  a  stretch  of  a  thousand 
miles,  representing  several  hundred  thousand  square  miles  of  contact.  It 
is  a  feature  of  southeastern  Asia,  from  latitude  30°  to  42°  north  and  longi- 
tude 108°  to  124°  east. 

Near  Ta-tung-fu  in  northern  Shan-si,  von  Richthofen  observed  an 
occurrence  of  characteristic  Sinian  limestones,  having  at  the  base  red,  clayey, 
and  calcareous  thin-bedded  deposits,  which  rest  unconformably  on  gneiss. 
He  remarks  that  the  "  Untersinisch,"  i.  e.,  the  Nan-k'ou  limestones,  are  here 
wanting.  The  occurrence  is  one  of  overlap  of  the  Cambrian  strata,  to 
which  we  restrict  the  term  Sinian,  beyond  the  pre-Cambrian,  Nan-k'ou, 
limestones  or  their  littoral  equivalents  onto  a  much  older  pre-Cambrian 
(Archean?)  gneiss.* 

*  China,  vol.  11,  p.  358. 


34  RESEARCH   IN   CHINA. 

A  similar  plane  of  unconformity  presumably  characterizes  northern 
Siberia,  where  the  great  plateau  of  flat  Paleozoic  strata  north  of  Irkutsk 
stretches  from  the  Lena  to  the  zone  of  folds  adjacent  to  the  Archean  areas 
along  the  Jenissei.  The  base  of  the  Paleozoic  is  there  Lower  Cambrian, 
and  the  surface  beneath  it  is  of  the  same  prolonged  cycle  as  that  in  south- 
western Asia. 

An  unconformity  comparable  with  that  at  the  base  of  the  Cambrian 
system  occurs  throughout  Central  Asia  also,  but  the  super jacent  strata  are 
probably  Devonian  or  Silurian.  The  surface  developed  on  the  pre-Cambrian 
rocks  is  therefore  younger  than  the  Sinian,  and  there  is  room  to  question 
what  features  existed  in  Central  Asia  during  the  Sinian  period.  It  is  prob- 
able that  the  epicontinental  sea  did  not  spread  over  the  entire  region  where 
the  corresponding  strata  are  now  absent,  although  it  no  doubt  covered  some 
part.  Whatever  land  area  was  exposed  at  any  stage  of  the  advance  and 
retreat  of  the  waters  was  then  being  eroded  and  furnished  the  sediment  of 
the  Sinian  strata,  which,  had  there  been  any  considerable  height  of  land, 
would  consist  of  shaly  and  sandy  deposits.  They  are,  however,  limestone, 
and  it  is  a  fair  inference  that  practically  all  Asia,  draining  to  the  Cambro- 
Ordovician  sea,  was  low  and  featureless. 

The  fact  that  Asia  at  the  opening  of  the  Paleozoic  era  was  a  featureless 
continent  has  important  bearings.  It  limits  the  antiquity  of  mountain 
ranges,  some  of  which  have  been  discussed  by  eminent  writers  as  of  pre- 
Cambrian  date,  as  elevations  which  have  survived  since  that  remote  time; 
and  it  affords  a  basis  of  inference  regarding  a  cycle  of  inactivity,  which  was 
common  to  other  continents  as  well. 


RESEARCH  IN   CHINA 


Southern  .  l.svV/   during  t/ti-   /'rr 


PLATE    3 


WU-  TXl  SERIES 
irea,  offyjjicaJ.  occurence  ) 


CHAPTER  El— EARLY  PALEOZOIC. 


SINIAN  SYSTEM  (CAMBRO-ORDOVICIAN). 

The  name  and  its  application. — Sinian  was  first  applied  by  Pumpelly 
to  the  prevailing  structural  axes  of  eastern  Asia,  which  trend  northeast  and 
southwest.*  It  was  adopted  by  von  Richthofen  to  designate  a  series  of 
conformable  strata  which  exhibit  folds  having  the  Sinian  direction.  They 
are  characterized  in  part  by  Cambrian  fossils,  but  were  believed  by  him  to 
extend  downward  below  the  base  of  the  Cambrian,  and  at  the  top  to  include 
part  of  the  Ordovician.  The  term  is  here  used  to  designate  the  Cambrian 
and  Ordovician  strata  to  which  he  applied  it,  but  those  limestones  which 
underlie  the  lowest  fossiliferous  Cambrian  are  excluded,  after  conference 
and  agreement  with  von  Richthofen  himself. 

The  problem  which  confronts  us  in  determining  the  base  of  the  Sinian 
is  inherent  in  the  more  or  less  local  nature  of  an  unconformity.  Each  un- 
conformity is  somewhere  represented  by  continuous,  conformable  deposits, 
and  the  area  of  unconformity  is  bounded  by  areas  of  conformity.  When 
we  pass  from  one  to  the  other  there  is  difficulty  in  dividing  the  con- 
tinuous series  of  strata  at  a  plane  corresponding  to  that  indicated  by  the 
discontinuity  in  the  neighboring  series.  This  condition  exists  at  the  base 
of  the  Cambrian  in  certain  localities  in  the  United  States,  where  the  lowest 
fossiliferous  Cambrian  strata  are  conformably  underlain  by  great  thick- 
nesses of  sediments,  that  accumulated  in  the  depressions  from  which  the 
Cambro-Ordovician  epicontinental  sea  expanded.  Such  sediments  are  by 
some  regarded  as  pre-Cambrian,  by  some  as  the  downward  extension  of 
the  Cambrian.  There  is  no  difference  of  opinion  regarding  the  base  in 
sections  where  the  unconformity  intervenes,  as  is  commonly  the  case. 

In  China  there  is  usually  an  unconformity  at  the  base  of  the  distinc- 
tive red  formation  of  the  Sinian,  and  Cambrian  fossils  occur  within  100  feet 
above  the  contact.  Von  Richthofen  observed  this  conspicuous  break,  and 
we  also  obtained  evidence  of  it  in  every  section  in  which  we  saw  the  appro- 
priate contact.  But  there  are  sections  such  as  that  of  the  Nan-k'ou  pass, 
northwest  of  Peking,  in  which  the  unconformity  was  not  noted  by  von  Richt- 
hofen and  may  not  exist.  The  strata  there  below  the  Cambrian  are  siliceous 
limestone,  equivalent  to  that  which  is  apparently  unconformable  beneath 

*  Smithsonian  Contributions  to  Knowledge,  vol.  xv,  Geological  Researches  in  China,  Mongolia,  and 
Japan,  p.  67.  Sinian  from  Sinim,  the  name  applied  to  China  in  the  earliest  mention  made  of  that 
country — in  Isaiah. 

"  35 


30  RESEARCH   IN   CHINA. 

Sinian  not  far  away,  at  Nan-t'ang-mei',  and  probably  equivalent  to  the 
Hu-t'o  system,  which  is  separated  from  the  Sinian  by  a  decided  break. 
Where  it  exists,  the  unconformity  is  everywhere  taken  as  the  dividing  plane 
and  the  equivalent  horizon  must  elsewhere  determine  the  limits  of  Cam- 
brian upon  pre-Cambrian,  even  though  the  strata  be  locally  conformable. 
Hence  we  are  constrained  to  exclude  from  the  Sinian  certain  limestones, 
which  von  Richthofen  regarded  as  "Untersinisch,"  but  which  in  all  prob- 
ability represent  deposits  that  are  pre-Sinian. 

Thus  used  to  name  a  series  of  conformable  strata  deposited  during  the 
great  Cambro-Ordovician  transgression  of  Asia,  the  term  Sinian  has  wide 
correlative  application,  since  a  similar  transgression  spread  over  much  of 
North  America  and  Europe  and  was  there  accompanied  by  evolution  of 
faunas  closely  related  to  those  of  Asia.  From  Cambrian  to  Ordovician 
there  is  general  continuity  of  physical  conditions  and  faunal  evolution.  A 
natural  plane  of  division  marked  by  unconformity  frequently  occurs  near 
the  middle  Ordovician.  The  strata  below  that  plane  to  the  base  of  the 
Cambrian  may  be  appropriately  called  Sinian.* 

Von  Richthofen  gives  the  following  description  of  the  Sinian  in  his 
chapter  on  the  rocks  of  Liau-tung  :f 

The  above-described  stratigraphic  fact  [a  marked  unconformity  of  dip]  sharply  dis- 
tinguishes the  formations  which  have  been  described  [pre-Cambrian  metamorphic  rocks 
and  intrusives]  from  a  series  of  strata  which  we  found  to  be  widely  distributed  along 
our  route.  In  regular  succession  they  follow  one  another.  They  everywhere  exhibit  a 
richly  varied  stratification,  which  in  the  upper  part  is  somewhat  monotonous,  but  in  the 
lower  shows  many  peculiarities  in  consequence  of  the  fact  that  the  strata,  which  were 
deposited  upon  a  sea  bottom  that  was  set  with  reefs,  extend  in  some  regions  deeper  than 
in  others.  At  a  certain  horizon  which  is  high  in  the  series  we  found  globulitic  limestones 
that  are  especially  distinct  and  afford  a  paleontological  clue.  According  to  a  communica- 
tion from  Mr.  Dames  the  trilobite  fauna  of  Sai-ma-ki  and  the  Tai-tsze  valley  consists 
essentially  of  the  genera  Dikelocephalus  and  Conocephalus,  and  is  closely  related  to  the 
fauna  of  the  Potsdam  sandstone  of  New  York,  Wisconsin,  Iowa,  and  Minnesota,  especially 
the  province  of  the  upper  Missouri,  and  the  relation  is  such  that  there  is  indeed  no  doubt 
of  their  equivalency.  In  the  Fortieth  Parallel  survey  the  same  fauna  has  been  recognized 
by  Hah1  in  the  mining  districts  of  White  Pine  and  Eureka.  It  seems  that  the  Chinese  fauna 
more  closely  resembles  the  American  Potsdam  fauna  than  the  Swedish  Cambrian.  It 
has  nothing  in  common  with  the  Bohemian  primordial  fauna. 

It  is  not  appropriate  to  apply  the  name  Cambrian  immediately  to  the  formation  under 
discussion.  For,  until  it  may  be  possible  to  distinguish  the  paleontological  horizon,  we 
are  obliged  to  assign  to  it  an  extraordinarily  long  sequence  of  strata,  which  constitutes  a 
great  whole  in  consequence  of  stratigraphic  conformity,  without  any  possibility  of  proving 
that  the  beginning  and  end  correspond  with  those  limits  within  which  the  name  Cambrian  is 

*A.  Geikie  has  translated  the  German  terra  "Sinisch"  as  "Sinisian."     The  original  English  form  used 
by  the  author  of  the  name  is  "Sinian." 
t  China,  vol.  u,  pp.  107-108. 


TYPE   SECTION  OP  SINIAN.  37 

applied  in  Europe  and  America.  It  is,  moreover,  possible  that  the  formation  in  China,  in 
which  strata  containing  the  primordial  fauna  have  indeed  a  definite  but  somewhat  subor- 
dinate position,  reaches  much  further  down  and  therefore  comprises  a  much  longer  period, 
while  it  also  probably  extends  without  noticeable  interruption  up  into  the  lower  Silurian. 

SINIAN  IN  CHINA. 

When  asked  to  suggest  a  district  in  which  the  Sinian  might  be  studied 
in  typical  character,  von  Richthofen  referred  us  to  I/iau-tung  and  Shan- 
tung, the  northeastern  provinces  of  China.  The  conditions  immediately 
preceding  war  rendered  surveying  in  L,iau-tung  difficult  at  the  time  of  our 
expedition,  and  Shan-tung  became  the  scene  of  our  detailed  studies. 

The  Ch'ang-hia  and  Sin-t'ai  districts  which  were  selected  for  detailed 
topographic  and  geologic  surveys  are  represented  in  plates  xin  and  xiv, 
volume  i,  and  the  local  variations  of  strata  are  described  by  Blackwelder, 
volume  i,  chapter  n.  The  general  sequence  consists  of  three  well-defined 
divisions  between  two  unconformities,  as  follows: 

Unconformity  by  erosion. 

Tsi-nan  limestone  (lower  Ordovician). 

Kiu-lung  group,  interbedded  limestone  and  shale  (Upper  and  Middle  Cambrian) . 

Man-t'o  shales  (Middle  and  late  Lower  Cambrian). 

Unconformity  by  dip. 

Pre-Cambrian  rocks. 

Lower  Sinian. — In  Shan-tung,  Ljau-tung,  and  Shan-si,  that  is,  through- 
out northern  China,  the  characteristic  strata  of  the  Lower  Sinian  are  red 
deposits,  which  we  have  called  the  Man-t'o  formation.  They  are  probably 
equivalent  to  von  Richthofen's  Tung-won  Schichten.  In  Central  China,  on 
the  Yang-tzi-kiang,  we  saw  nothing  corresponding  to  the  Man-t'o  formation, 
the  Sinian  being  composed  of  limestone,  apparently  to  the  very  base. 

The  typical  red  shale  of  the  Man-t'o  formation  passes  into  red  or 
chocolate-brown  shaly  sandstone  and  is  interbedded  with  thin  but  some- 
times persistent  layers  of  gray  to  cream-colored  limestone.  The  thick- 
ness varies  from  350  to  550  feet,  105  to  165  meters.  The  basal  layers 
occasionally  show  local  conglomerates,  as  at  Nan-t'ang-mei',  Shan-si,  where 
a  body  of  chert  conglomerate  rests  upon  cherty  Proterozoic  limestone, 
and  south  of  Tung-yu,  Shan-si,  where  the  underlying  slates  of  the  Hu-t'o 
system  constitute  pebbles  in  the  Man-t'o  next  the  contact.  Usually,  how- 
ever, the  material  adjacent  to  the  eroded  surface  of  pre-Cambrian  rocks  is 
highly  oxidized  residual  soil  or  fine  calcareous  sediment,  which  is  in  either 
case  foreign  to  the  underlying  metamorphic  rocks. 

The  sandy  red  mud  of  the  Man-t'o  formation  is  an  end-product  of 
mechanical  and  chemical  rock  decay.  Only  the  most  enduring  minerals, 


38  RESEARCH   IN   CHINA. 

quartz,  clay,  and  oxide  of  iron,  remain  in  notable  quantities.  The  material 
resulted  from  disintegration  of  crystalline  rocks  under  climatic  condi- 
tions favorable  to  oxidation,  or  passed  through  stages  of  accumulation 
as  a  continental  deposit,  during  which  it  was  subject  to  such  conditions, 
and  was  laid  down  without  undergoing  chemical  reduction  or  abrasion  or 
sorting.  The  rock  is  red  throughout,  as  the  Permian  and  Triassic  sand- 
stones are,  and  like  them  was  not  only  originally  a  red  mud,  but  formed 
a  red  deposit.  It  did  not  become  blue,  as  the  red  muds  of  Virginia  now 
do  in  Chesapeake  Bay  in  consequence  of  abundant  organic  matter.  The 
persistence  of  red  in  the  Man-t'o  formation  shows  that  organic  substances 
were  not  present  in  quantity. 

Waves,  of  which  ripple  marks  on  the  sandy  shales  are  here  and  there 
evidence,  accomplished  but  little  work  in  the  way  of  sorting.  They  were 
evidently  too  weak  to  sort  sediment  in  which  the  proportion  of  mud  was 
so  great. 

Calcareous  layers  occur  in  the  Man-t'o  formation  occasionally  very 
near  the  base,  persistently  at  horizons  100  to  150  feet,  30  to  45  meters, 
higher  up,  and  again,  less  commonly,  near  the  top,  which  is  often  sandy. 
A  transition  into  the  overlying  limestone  of  the  Kiu-lung  group  is  formed  of 
interbedded  brown  shale  and  gray  limestone.  Individual  limestone  strata 
are  very  uniform  in  thickness,  though  but  a  few  inches,  or  at  most  10  feet, 
thick  and  not  of  great  extent.  The  more  continuous  are  those  near  the 
middle  of  the  formation,  which  were  found  in  all  the  sections  in  the  Ch'ang- 
hia  and  Sin-t'ai  districts  in  Shan-tung. 

The  interbedding  of  the  shale  and  limestone  is  irregular;  it  does  not 
follow  any  rhythm.  It  is  apparent  that  local  conditions  were  unlike  in 
adjacent  waters  at  any  one  time  and  varied  in  unlike  manner  from  time  to 
time;  but  red  sediment  from  the  land  or  calcareous  sediment  from  the  sea 
was  deposited  at  any  time.  The  condition  which  favored  precipitation 
of  lime,  whether  chemically  or  organically,  was  continuously  present  and 
became  effective  whenever  the  environment  became  right;  and  so  with 
the  mud.  It  is  not  possible  to  assume  that  the  limestones  were  laid  down 
in  deep  waters;  they  are  too  closely  related  to  the  shales  and  sandstones 
which  were  deposited  in  shallows.  As  the  limestones  are  relatively  free 
from  clay,  and  what  they  do  contain  is  very  fine,  the  lime-depositing  waters 
were  comparatively  clear,  and  this  clearness  appears  to  have  been  the 
essential  condition. 

One  may  form  a  concept  of  the  conditions  somewhat  as  follows:  Along 
the  flat,  red  shore  of  the  Man-t'o  sea,  bars  and  islands  formed  where  streams 
emptied,  and  shut  off  the  mud-carrying  currents  from  intermediate  stretches 
of  coast.  More  or  less  extensive  lagoons  were  thus  produced  and  within 


SINIAN  GLACIAL  DEPOSIT.  39 

these  the  waters  were  clear.  Being  partly  closed  and  shallow,  they  were 
relatively  warm  and  liable  to  maximum  evaporation.  Rippling  of  the 
surface  favored  precipitation  of  lime  carbonate  by  agitation.  Warmth 
and  protection  invited  organic  life,  both  plant  and  animal,  which  probably 
occupied  the  lagoons  in  low  forms  that  did  not  become  fossil  before 
trilobites,  the  earliest  that  have  been  preserved,  discovered  the  habitat. 

The  description  of  the  Man-t'o  formation  has  thus  far  dealt  with  it 
as  it  is  developed  in  northern  China.  The  red  mud  does  not  occur  in  the 
south  on  the  Yang-tzi'-kiang,  where  we  saw  the  base  of  the  Sinian,  but  the 
strata  which  we  suppose  to  be  equivalent  are  thin-bedded  gray  limestones 
which  rest  on  a  well-defined  glacial  till.  The  latter  was  seen  only  near  the 
village  of  Nan-t'ou,  and  we  have  named  it  the  Nan-t'ou  tillite. 

Nan-t'ou  tillite. — The  Nan-t'ou  glacial  deposit  occurs  in  longitude 
in0  east,  latitude  31°  north,  about  200  feet,  60  meters,  above  sea.  It 
evidently  accumulated  close  to  sea-level  in  early  Sinian  time,  as  it  is 
overlain  by  marine  limestones  of  that  age.  At  the  base  the  plane  of  the 
pre-Sinian  unconformity  is  characteristically  developed  and  covered  by 
a  cross-bedded  quartzite,  which  may  have  been  either  river  deposit  or 
beach.  The  top  of  the  quartzite  is  generally  covered  in  the  type  locality 
and  a  cultivated  slope  interrupts  the  section  for  100  feet,  30  meters.  Above 
the  terraced  fields  occur  steep  banks  of  tillite,  a  greenish  rock,  about  as 
hard  as  unweathered  shale,  of  irregular  hackly  fracture,  not  stratified,  and 
containing  pebbles  and  boulders  of  various  kinds  and  sizes,  many  of  which 
are  striated.  The  thickness  seen  is  120  feet,  36  meters. 

At  the  top  of  the  tillite,  beneath  a  cliff,  is  a  well-exposed  contact  with 
the  overlying  limestone.  The  tillite  passes  into  a  greenish  shale,  consisting 
of  the  same  materials,  including  characteristic  pebbles,  all  rearranged  by 
water.  This  shale  conglomerate  is  about  2  feet  thick  and  grades  into  the 
overlying  limestone,  the  basal  layer  of  a  great  thickness  of  Sinian. 

The  facts  clearly  demonstrate  the  presence  at  this  spot  of  a  glacier 
which  gave  way  to  marine  waters  and  left  a  deposit  of  till  that  was  slightly 
washed  by  waves  before  it  was  buried  beneath  calcareous  mud. 

The  glacial  deposit  was  seen  only  where  it  is  exposed  in  the  gorge  of  the 
Yang-tzi'-kiang,  beneath  limestone  cliffs.  Both  northward  and  southward 
from  the  river  the  escarpment  stretches  beyond  sight,  and  continuous 
below  it  is  the  slope  which,  at  the  river,  is  formed  of  the  tillite;  but  so 
common  a  topographic  feature  as  a  slope  below  a  cliff  affords  little  ground 
for  inferring  the  extension  of  so  unusual  a  deposit  as  an  early  Cambrian 
till,  and  we  limit  ourselves  to  the  positive  statement  of  occurrence  at 
Nan-t'ou. 


40  RESEARCH  IN  CHINA. 

Whether  the  Nan-t'ou  glacier  was  an  exceptional  occurrence  or  a  rep- 
resentative of  an  extensive  system,  only  in  degree  affects  the  deduction 
that  the  temperature  of  early  Sinian  time  was  low.  Glaciation  in  latitude 
31°  near  sea-level  presents,  it  is  true,  a  problem  which  refrigeration  alone 
will  not  solve,  especially  as  no  traces  of  contemporaneous  glaciers  have  been 
found  further  north ;  but  there  can  be  no  doubt  that  it  signifies  severe  cold 
throughout  northern  Asia.  The  fact  agrees  with  the  inference  which  may 
be  drawn  from  the  red  sediments  of  the  Man-t'o.  That  they  were  not 
reduced  by  organic  matter  proves  the  barrenness  of  the  shores  and  seas, 
although  life  was  abundant  elsewhere  before  and  during  the  Man-t'o  epoch 
and  soon  after  developed  richly  in  the  shallows;  that  it  was  at  first  absent 
and  when  it  appeared  in  the  sea  was  limited  in  variety  may  be  attributed 
to  the  low  temperature. 

Aridity  was  also  probably  a  condition  of  the  climate.  Slight  precipi- 
tation prevents  glaciation,  even  under  conditions  of  severe  cold,  as  is  the 
case  in  northern  Siberia,  and  the  absence  of  glaciers  in  the  north  in  early 
Sinian  time  may  thus  be  understood. 

Middle  Sinian,  Kiu-lung  group. — The  Kiu-lung  group  of  Shan-tung  is 
a  succession  of  limestones  and  shales  which  immediately  follows  the  Man-t'o 
formation.  Transition  beds  connect  the  two.  Shale  is  a  common  rock  in 
both,  but  in  the  Man-t'o  it  is  red,  whereas  in  the  Kiu-lung  it  is  green.  Lime- 
stone is  thin-bedded  and  subordinate  in  the  former,  in  the  latter  it  is  usually 
massive  and  predominant.  The  Man-t'o  contains  a  sparse  Middle  or  Lower 
Cambrian  fauna  in  its  upper  portion;  the  Kiu-lung  carries  very  abundant 
faunas,  which  range  from  Middle  Cambrian  at  the  base  to  Upper  Cambrian 
and  possibly  to  lowest  Ordovician  at  the  top. 

This  Cambrian  group  was  clearly  recognized  in  Shan-tung,  but  not  as 
distinctly  elsewhere.  In  Shan-si  it  is  represented  by  the  lower  part  of  the 
Ki-chou  limestone,  which  comprises  all  the  Sinian  except  the  Man-t'o  shale ; 
and  on  the  Yang-tz'i  the  Kiu-lung  horizons  are  within  the  great  limestone 
formation,  which  is  the  whole  Sinian  system. 

I  proceed  to  consider  the  Kiu-lung  group  as  it  occurs  in  Shan-tung. 
The  type  locality  is  the  Kiu-lung  range,  a  chain  of  hills  which  borders  the 
Won -ho  valley  on  the  south,  southeast  of  the  district  town  of  Lai-wu-hien, 
longitude  117°  40'  E.,  latitude  36°  15'  N.  The  strata  dip  gently  northward 
and  are  extensively  exposed  from  the  Man-t'o  shale  below  to  the  Tsi-nan 
limestone  above.  The  thickness  is  900  to  1,000  feet,  275  to  335  meters. 

The  component  strata  are  of  green  shale  and  limestone.  The  latter 
presents  several  distinct  varieties:  massive  black  to  gray  oolite,  nodular 
or  conglomeratic  layers  of  shale,  and  uniform  fine-grained  blue  limestone. 
These  occur  from  the  bottom  up,  in  the  order  named,  of  such  thickness  and 
extent  as  to  be  considered  distinct  formations  in  some  districts. 


CHARACTER  OF   MIDDLE   SIMIAN.  41 

The  black  oolitic  limestone,  which  commonly  but  irregularly  occurs 
in  the  green  shale  above  the  red  Man-t'o,  reached  a  maximum  thickness, 
as  we  observed  it,  of  550  feet,  165  meters,  near  the  village  of  Ch'ang-hia,* 
and  we  called  it  the  Ch'ang-hia  oolite.  In  consequence  of  its  massive 
character  and  vertical  jointing  it  there  forms  imposing  cliffs,  and  one  does 
not  suspect  that  it  may,  in  a  short  distance,  thin  out  to  a  layer  of  vanish- 
ing lenses.  Such  is,  however,  the  case,  as  we  found  in  the  district  north 
of  Sin-t'ai-hien,  where  a  stratum  100  feet,  30  meters,  thick  gave  out  in 
less  than  a  mile.  The  color  of  the  rock  is  due  to  the  black  oolites,  with 
which  it  is  usually  crowded.  Blackwelder  has  described  their  peculiarities^ 
and  he  finds  that  there  is  a  series  of  forms  ranging  from  true  oolites, 
which  exhibit  a  nucleus  and  concentric  banding,  through  grades  of  finer 
to  coarser  crystalline  texture,  to  a  single  crystal;  and  he  concludes  that  all 
the  bodies  had  a  common  origin  as  oolites,  which  formed  concentrically 
around  a  nucleus.  Some  have  remained  but  little  altered  and  show  the 
original  structure,  while  others  have  more  or  less  completely  crystallized. 
Crystallization  has  progressed  from  a  primary  condition  of  many  minute 
crystals  toward  an  ultimate  development  of  a  few  or  one  large  crystal.  The 
fossils  of  the  Ch'ang-hia  limestone  are  trilobites,  brachiopods,  etc.,  of  Middle 
Cambrian  age. 

The  middle  portion  of  the  Kiu-lung  group  is  characterized  by  the 
predominance  of  shale.  In  the  vicinity  of  Ch'ang-hia  a  single  stratum  150 
feet,  45  meters,  thick  was  so  clearly  distinct  that  we  described  it  as  a  sep- 
arate formation,  the  Ku-shan  shale.  In  the  Kiu-lung  hills  and  adjacent 
areas,  however,  no  individual  shale  formation  was  distinguishable,  the  mass 
of  shale  and  limestone  layers  being  on  the  whole  thicker,  but  irregular. 

A  special  interest  attaches  to  this  member,  since  conglomeratic  lime- 
stones, such  as  have  been  described  by  Walcott  as  "  intraformational 
conglomerates,"  are  of  common  occurrence  in  it.  These  peculiar  rocks 
consist  of  an  earthy  calcareous  matrix,  in  which  flat,  pebble-like  bits  of 
limestone  are  irregularly  embedded.  The  pieces  are  commonly  rounded, 
but  sometimes  sharply  broken ;  they  are  fragments  of  thin  limestone  sheets, 
which  were  broken  up,  washed,  and  rearranged  during  the  formation  of  the 
stratum  in  which  they  occur.  Among  the  hypotheses  that  have  been  sug- 
gested to  account  for  these  conglomerates,  we  are  restricted  to  those  which 
regard  the  pebbles  and  the  matrix  as  essentially  contemporaneous.  The 
fact  of  unbroken  conformity  with  the  immediately  underlying  stratum, 
which  has  been  observed  in  every  instance,  excludes  any  hypothesis  that 
presupposes  unconformity  and  erosion  of  older  rocks.  Identity  of  earthy 
calcareous  composition  of  pebble  and  matrix,  and  particularly  identity  of 

*Vol.  i,  Plate  xiii. 
f  Ibid.,  p.  30. 


42  RESEARCH   IN   CHINA. 

fossil  content  in  both,  confirms  this.  Characters  common  to  shoal-water 
deposits  mark  these  beds,  which,  though  most  frequent  in  the  middle  of  the 
Kiu-lung  group,  occur  also  in  the  underlying  Man-t'o.  The  conditions  of 
occurrence,  the  constitution,  and  the  detail  of  the  conglomeratic  layers 
require  that  during  the  deposition  of  calcareous  mud  in  shallow  waters  there 
shall  have  been  some  layers  that  hardened  more  or  less  firmly  to  limestone 
strata.  There  is  no  evidence  that  they  were  extensive  or  continuous;  they 
may  probably  have  been  limited  and  separate;  but  they  were  common. 
The  mud  containing  these  layers  was  disturbed  and  the  more  or  less  con- 
solidated lime  rock  was  broken,  washed,  and  redeposited,  after  the  manner 
of  a  conglomerate.  A  portion  of  the  process  as  yet  eludes  interpretation. 
We  do  not  know  the  physico-chemical  or  organic  conditions  under  which 
limestones  consolidate,  and  are  therefore  at  a  loss  to  understand  why  some 
layers  or  nodules  harden  before  others.  Our  speculations  are  given  in  vol- 
ume I,  part  ii. 

The  upper  part  of  the  Kiu-lung  group  is  a  thick-bedded  uniform  lime- 
stone, of  light-blue  to  gray  color  and  usually  smooth  texture.  From  its 
development  near  the  village  of  Ch'au-mi-tien  in  the  Ch'ang-hia  district, 
we  called  it  the  Ch'au-mi-tien  limestone.  Its  thickness  is  about  580  feet, 
175  meters,  in  the  type  locality,  where  it  directly  overlies  the  Ku-shan 
shale.  In  Kiu-lung  hills  the  rock  occupies  a  similar  stratigraphic  horizon 
and  carries  the  Upper  Cambrian  fossils,  which  characterize  it  in  the  type 
locality,  but  its  limits  are  not  so  clearly  defined.  In  marked  contrast  to 
other  Sinian  strata  below  it,  the  Ch'au-mi-tien  limestone  is  horizontally 
continuous  and  uniform.  It  represents  a  wide-spread  condition  of  deposi- 
tion, such  as  the  circulation  of  a  broad  marine  current  over  a  continental 
shelf,  and  thus  differs  from  the  strictly  littoral  aspects  of  the  Man-t'o 
terrane,  and  the  inconstant  phases  of  the  shaly  part  of  the  Kiu-lung 
division. 

Upper  Sinian. — The  Tsi-nan  limestone,  so  named  after  the  capital 
city  near  which  it  is  exposed,  is  the  highest  formation  of  the  Sinian  system 
in  Shan-tung.  It  differs  from  the  underlying  Ch'au-mi-tien,  being  less 
plainly  stratified,  dark  gray  to  brownish  in  color,  and  poor  in  fossils,  which 
are  of  lower  Ordovician  types.  It  may  commonly  be  divided  into  two 
members :  a  lower,  250  feet,  75  meters,  thick,  consisting  of  shale  and  coarse 
crystalline  dolomite,  which  weathers  like  calcareous  sandstone;  and  an 
upper,  2,500  feet,  750  meters,  or  more,  which  is  dolomitic  limestone.  The 
total  thickness  is  indeterminate,  since  the  upper  surface  is  one  of  erosion, 
even  where  it  is  covered  by  later  sediments. 

This  Ordovician  limestone  was  confused  by  von  Richthofen,  who  found 
no  fossils  in  it,  with  the  very  similar  Carboniferous  formation  that  he  had 


DIVISIONS  OF  THE   SINTAN. 


43 


correctly  identified  in  southern  China,  and  it  is  erroneously  represented 
as  "  Kohlenkalkstein  "  in  his  published  maps  of  northern  China.  Lorenz* 
in  1902  and  Blackwelder  in  1903  independently  recognized  its  Ordovician 
relation  on  the  basis  of  few  but  characteristic  fossils.  Weller  has  described 
our  collections.! 

Sinian  in  general. — The  development  of  the  Sinian  system  in  Shan- 
tung, where  the  Man-t'o  red  shales,  the  Kiu-lung  group  of  green  shale  and 
varied  limestone,  and  the  Tsi-nan  dolomitic  limestone  are  distinguishable, 
is  better  known  to  us  than  the  sequence  of  corresponding  strata  in  any  other 
province.  The  Man-t'o  is  present  in  northwest  Chi'-li  and  Shan-si,  and  is 
there  followed  by  peculiar  limestones  like  those  of  the  Kiu-lung.  Von 
Richthofen  observed  the  same  characteristic  rocks  in  northern  Ho-nan, 
latitude  34°  30'. J  The  red  shale  is  wanting  in  the  sections  we  saw  on  the 
Yang-tz'i-kiang,  but  the  conglomeratic  and  oolitic  limestones  are  present. 
These  varied  relations  led  us  to  apply  local  names  to  the  divisions  which 
are  unlike  in  different  provinces.  Their  correlative  significances  are  given 
in  the  following  table: 


System. 

Shan-tung. 

Liau-tung. 

Chi-li  and  Shan-si. 

Ssi-ch'uan  and  Hu-peif. 

Sinian 

(Tsi-nan  limestone  1 
V  Kiu-lung  group  / 
V  Man-t'o  shale 

Fu-ch6u  ?  group 
Yung-ning  sandstone 

Ki-ch6u  limestone 
Man-t'o  shale 

Ki-sin-ling  limestone 
Nan-t'ou  tillite 

The  following  paragraphs  contain  a  summary  of  our  observations 
regarding  the  Sinian  in  Shan-si  and  the  Ki-sin-ling  limestone  of  the  Yang- 
tzi  gorges,  Hu-pei.  § 

In  northern  Shan-si,  about  the  Wu-t'ai-shan,  the  Sinian  is  exposed 
in  characteristic  development,  with  the  Man-t'o  at  the  base  and  the  cal- 
careous strata  in  great  thickness  above.  The  lowest  stratum  of  the  Man-t'o 
is  frequently  a  conglomerate  of  pebbles  of  the  subjacent  rocks,  and  the 
materials  of  the  formation  are,  throughout  its  thickness,  coarser  than  is 
commonly  the  case  in  Shan-tung.  The  characteristic  yellowish  limestones 
occur,  but  generally  high  up  and  in  two  or  three  layers  only.  The  total 
thickness  is  180  to  335  feet,  55  to  100  meters. 

Strata  of  gray  to  greenish  shale  and  oolitic  as  well  as  conglomeratic 
limestone,  aggregating  about  600  feet,  180  meters,  succeed  the  red  rocks 
and  correspond  to  part  of  the  Kiu-lung  group.  Above  these  follow  massive 

*  Beitrage  zur  Geologic  und  Paleontologie  Shan-tungs,  Lorenz,  part  I. 

t  Vol.  in  of  this  work. 

J  China,  vol.  n,  p.  505. 

§For  fuller  details  see  vol.  i,  chapters  vi  and  xii. 


44  RESEARCH   IN   CHINA. 

limestones,  which  are  the  equivalents  of  the  Ch'au-mi-tien  and  Tsi-nan 
divisions  and  compare  with  them  in  massiveness.  The  total  thickness  of 
the  system  in  northern  Shan-si  is  not  far  from  4,000  feet,  1,200  meters. 

On  the  middle  Yang-tz'i,  in  Hu-pei  and  eastern  Ss'i-ch'uan,  the  Sinian 
is  represented  by  a  limestone  which  is  4,500  to  5,000  feet,  1,350  to  1,500 
meters,  thick.  The  great  formation  is  probably  capable  of  subdivision  on 
lithologic  and  paleontologic  differences,  but  the  distinctions  are  less  marked 
than  in  Shan-tung  or  even  in  Shan-si.  Regarding  it  as  a  whole  it  may  be 
called  the  Sinian  limestone,  but  to  give  it  sharper  definition  we  apply  the 
name  Ki-sin-ling,  from  the  pass  of  that  name  where  the  provinces  of  Hu-pei, 
Ssi'-ch'uan,  and  Shen-si  corner.  It  is  there  typically  exposed,  and  both 
Cambrian  and  Ordovician  fossils  were  found  in  nearby  sections. 

At  the  base  of  the  Ki-sin-ling  limestone,  at  Nan-t'ou  on  the  Yang-tz'i, 
is  a  basal  conglomerate  of  pebbles  derived  from  the  underlying  tillite, 
embedded  in  greenish  shale.  It  is  but  two  feet  thick  and  is  succeeded  by 
thin-bedded,  shaly,  oolitic,  and  in  part  chert-bearing  limestones,  350  feet 
thick.  We  did  not  see  the  bottom  of  the  formation  in  any  other  section, 
but  the  thin-bedded  limestones  probably  appear  in  the  gorges  of  the  Yang- 
tzi  and  in  the  mountains  near  the  Ki-sin-ling. 

The  upper  and  major  part  of  the  Sinian  in  the  Yang-tz'i  sections  is 
massive  dark-gray  or  liver-colored  limestone,  free  from  chert.  It  is  prob- 
ably nearly  4,500  feet,  i  ,350  meters,  thick.  Farther  north  in  the  Ki-sin-ling 
pass,  it  consists  of  thinner  bedded,  more  carbonaceous  or  bituminous 
strata.  It  is,  however,  in  all  its  phases  a  great  marine  limestone. 

The  upper  limit  of  the  Ki-sin-ling  is  indeterminate,  as  there  is  a  tran- 
sition from  it  into  interbedded  shale  and  limestone,  which  passes  upward 
into  the  overlying  Sin-t'an  shale.  The  transition  strata  are  between  200 
and  300  feet,  60  to  90  meters,  thick,  and  at  Sii-kia-pa  in  Ssi'-ch'uan  they 
yielded  middle  Ordovician  (Trenton)  fossils.  The  horizon  is  lithologically 
distinguished  by  a  peculiar  stratum  of  black  chert  or  lydite,  which  was  also 
found  by  von  Richthofen  and  L6czy  in  sections  north  of  Kuan-yiian-hien, 
Ss'i-ch'uan,  200  miles,  300  kilometers,  northwest  of  Sii-kia-pa. 

The  age  of  the  lower  part  of  the  Ki-sin-ling  is  not  definitely  fixed,  as  we 
found  no  fossils  at  Nan-t'ou,  where  the  base  is  exposed;  and  those  which 
we  did  find  elsewhere  were  obtained  from  pebbles.  They  were  picked 
up  on  a  river  bar  of  the  Nan-kiang,  near  Chon-p'ing-hien,  Shen-si,  where 
strata  of  the  Ki-sin-ling  form  the  canyon  walls,  and  they  no  doubt  came 
from  the  immediate  vicinity  and  from  the  lower  part  of  the  limestone. 
They  comprise  Lower  Cambrian  Obolus  asiatica  as  well  as  lower  Middle 
Cambrian  types,  and  represent  the  top  of  the  Man-t'o  and  base  of  the 
Kiu-lung  group  of  Shan-tung. 


SINIAN  IN  THE  TS'lN-UNG.  45 

The  Ki-sin-ling  thus  includes  at  least  upper  Lower  Cambrian  at  the 
base,  and  extends  up  to  middle  Ordovician  (Trenton),  at  which  horizon 
it  passes  by  transition  into  shales,  which  are  probably  of  Silurian  or 
Devonian  age. 

Sinian  strata  are  not  definitely  known  by  fossils  to  occur  southeast  of 
the  Yang-tzi'  in  southeastern  China,  but  both  von  Richthofen  and  Loczy,* 
with  strong  probability,  refer  certain  strata,  the  Ta-ho  grits  and  Lu-shan 
slates,  to  the  period. 

Sinian  strata  have  not  been  recognized  in  characteristic  limestones  or 
identified  by  fossils  in  the  Ts'in-ling-shan,  yet  they  are  in  all  probability 
present.  Von  Richthofen  did  not  hold  this  view.f  He  wrote: 

The  eastern  Kuen-lung  remained  free  from  the  Sinian  transgression  south  of  the 
northern  base  of  the  Fu-niu-shan  and  the  Ts'in-ling-shan,  and  the  adjacent  region  on  the 
south. 

Briefly  the  facts  are  as  follows:  In  three  sections  across  the  Ts'in-ling 
range,  observed  by  von  RichthofenJ  and  ourselves,  metamorphic  schists  of 
the  Wu-t'ai  type  are  succeeded  by  a  basal  conglomerate,  quartzitic  rocks, 
and  gray  limestone.  There  is  a  great  series  of  slates,  and  also  carbonace- 
ous limestone,  which  locally  carries  coal.  Our  observations  of  the  relations 
of  these  strata  are  delineated  on  the  geological  atlas  sheet  ai,  and  while  not 
conclusive,  they  indicate  that  the  order  of  stratigraphic  sequence  is  from  the 
conglomerate,  through  quartzite,  limestone,  and  slate,  to  the  coal-bearing 
limestone.  We  agree  with  von  Richthofen  that  the  last-named  is  Carbon- 
iferous, but  think  it  is  distinct  from  the  gray  limestone,  which  corresponds 
with  the  Ki-sin-ling  (Sinian)  in  position  beneath  a  thickness  of  middle 
Paleozoic  shales.  If  our  understanding  is  correct,  the  Sinian  is  present  in  a 
mid-section  of  the  Ts'in-ling-shan,  near  the  northern  base  of  the  range. 

There  is  but  little  knowledge  regarding  the  Sinian  system  northwest  of 
the  Ts'in-ling-shan.  Loczy  assigns  various  occurrences  of  limestone,  which 
he  describes  as  early  Paleozoic,  to  the  system,  but  as  a  rule,  in  the  fact  that 
they  are  highly  siliceous,  they  much  more  nearly  resemble  the  pre-Cambrian 
limestones  of  the  Nan-k'ou  system  than  they  do  the  Sinian.  However,  in 
the  vicinity  of  Que-ta,  latitude  36°,  longitude  102°,  west  of  Lan-ch6u-fu,  he 
observed  in  a  small  mountain  range  known  as  the  "Cha-ji-shan"  a  heavily 
bedded  limestone,  in  part  dark  and  bituminous,  in  part  lighter  colored  and 
somewhat  interbedded  with  shale  and  sandstone,  which  exhibits  an  oolitic 
nodular  structure  such  as  is  found  also  in  the  globulitic  limestones  of  the 
Sinian.  He  regards  this  as  a  characteristic  occurrence  of  the  Sinian  lime- 

*Reise  des  Orafen  Sz6chenyi,  vol.  i,  p.  380,  map. 
t  China,  vol.  n,  p.  713. 
id.,  vol.  n,  p.  565. 


46  RESEARCH   IN   CHINA. 

stone  of  sufficiently  definite  character  to  justify  the  identification  of  it  and 
other  limestones  of  the  region  as  belonging  to  that  system. 

In  the  preceding  pages  the  occurrence  of  the  early  Paleozoic  (Sinian) 
strata  has  been  described  for  various  districts  of  China,  from  the  province 
of  Liau-tung,  latitude  41°,  to  the  Yang-tzi  in  latitude  30°;  and  from  the 
eastern  plains  of  the  empire  to  the  central  Ts'in-ling-shan,  in  longitude  108°. 
It  remains  to  consider  the  probably  equivalent  terranes  which  are  known 
in  the  Himalayas. 

In  southwestern  China  rocks  of  early  Paleozoic  age,  if  they  occur,  are 
highly  metamorphosed  and  have  not  yet  been  definitely  recognized.  It  is 
not  until  we  reach  the  central  Himalayas,  in  longitude  80°,  that  we  have 
any  precise  information.  Thence  westward,  in  the  regions  covered  by 
Griesbach*  and  Hayden.f  there  exists,  on  the  basis  of  fossils,  definite 
evidence  of  the  presence  of  the  Upper  Cambrian,  which  is  underlain 
by  a  considerable  thickness  of  conformable  strata,  presumably  also  of 
Cambrian  age. 

Griesbach  calls  these  strata  by  the  local  name  Haimantas,  and  gives 
the  following  classification  for  the  eastern  area: 

In  descending  order: 

Silurian : 

3.  Series  of  quartz  shales  and  slates. 

2.  Shales  and  silky  phyllites,  with  great  thickness  of  quartzites. 
Haimantas : 

i .  Quartzite,  generally  purple,  with  great  thickness  of  conglomerate. 
Vaikritas  and  older  gneiss.     (Pre-Cambrian.) 

The  total  thickness  is  estimated  at  about  4,000  feet,  1,200  meters.  The 
base  where  the  Haimantas  come  in  contact  with  the  Vaikritas  exhibits  no 
sharply  defined  plane  of  division : 

At  Milam,  for  instance,  there  is  seemingly  a  very  gradual  passage  from  the  micaceous 
schist  south  of  that  village,  into  greenish-gray  phyllites  and  talcose  schists  with  garnets  of 
the  Vaikritas,  and  finally  into  the  thin-bedded  quartzites,  shales,  and  conglomerates  of  the 
Haimantas,  and  the  change  is  so  gradual  that  the  boundary  line  could  not  be  drawn  with 
anything  like  accuracy.! 

Regarding  the  conglomerate,  it  is  said  (page  51) : 

The  thick  deposits  of  a  coarse  conglomerate  and  breccia  are  mostly  made  up  of  rolled 
and  subangular  fragments  of  rocks  belonging  to  the  crystalline  area,  and  amongst  them 
large  boulders  of  quartzites  and  gneissose  rocks  seem  to  predominate.  The  matrix  in  which 


*  India  Geological  Survey  Memoirs,  vol.  xxm,  Geology  of  the  Central  Himalayas,  by  C.  L.  Gries- 
bach, 1891. 

•\Idem,  vol.  xxxvi,  pt.  I,  Geology  of  Spiti,  with  parts  of  Bashahr  and  Rupshu,  by  H.  H.  Hayden, 
1904. 

%Idem,  vol.  xxm,  p.  51. 


CAMBRIAN   IN   THE  HIMALAYAS.  47 

these  boulders  are  firmly  embedded  is  nearly  always  a  hard  flinty  quartz  rock,  sometimes 
partially  schistose.  It  is  by  far  one  of  the  most  characteristic  and  easily  recognized  hori- 
zons of  the  central  Himalayas,  and  is  invariably  met  with  in  all  Haimanta  sections  which  I 
have  seen. 

Again  on  page  96: 

This  conglomerate,  which  in  places  strongly  resembles  a  boulder-bed,  merges  into 
massive,  intensely  hard,  dark-purple  quart/ites. 

And  on  page  159: 

The  mineralogical  character  of  the  shales  and  quartzites  lying  below  the  typical 
purple  quartzites  with  the  boulder-bed  (conglomerate)  and  the  adjoining  metamorphic 
schists,  Vaikritas,  merge  into  one  another. 

It  is  of  interest  to  note  the  descriptive  term,  "  boulder-beds,"  by  which 
the  conglomerates  of  the  early  Cambrian  are  designated,  since  we  have  dis- 
covered glacial  deposits,  probably  of  that  age,  on  the  Yang-tzi,  in  a  region 
which,  though  1,850  miles,  3,000  kilometers,  distant,  is  practically  in  the 
same  latitude,  31°  north.  However,  the  conglomerate  was  not  regarded  as 
a  true  boulder-bed  of  glacial  origin  by  Griesbach,  who,  with  reference  to 
the  ancient  shore-line  in  the  western  Himalayas  during  the  Haimanta  age, 
states  that  he  regards  these  deposits  to  be  evidence  of  "a  chain  of  eleva- 
tions, from  the  waste  of  which  the  boulders  and  pebbles  of  the  Haimanta 
conglomerate  were  derived."  An  inquiry  addressed  to  Dr.  Holland,  the 
present  director  of  the  Indian  Survey,  has  brought  a  negative,  though 
perhaps  not  decisive,  answer: 

The  question  of  the  possible  existence  of  Pre-Carboniferous  glacial  deposits  in  India  is 
one  which  has  recently  received  considerable  attention.  You  are,  no  doubt,  familiar  with 
the  published  description  of  the  Blaini  boulder  slate  of  the  Simla  area,  the  glacial  origin  of 
which  is  generally  admitted.  This  formation  was,  until  recently,  regarded  as  possibly  of 
Upper  Paleozoic  age,  corresponding  to  the  well-known  Talchir  and  Salt  Range  boulder- 
beds;  but  there  has  been  of  late  a  general  tendency  to  correlate  the  series  of  beds  with  which 
it  is  associated  with  the  old,  probably  Pre-Cambrian,  sediments  of  the  Peninsula.  I  first 
drew  attention  to  this  in  my  General  Report  of  the  Geological  Survey  (1903-04)  published 
in  Records  Geological  Survey  of  India,  vol.  xxxn  (page  156)  and  the  conclusion  based 
admittedly  on  negative  evidence  has  received  some  support  from  the  recent  discoveries  of 
Pre-Cambrian  boulder  slates  both  in  Australia  and  in  South  Africa.  In  this  connection, 
the  occurrence  of  a  typical  boulder  slate  among  the  pre-Vindhyan  rocks  of  the  Son  Valley  in 
Rewa  State  is  also  of  considerable  interest  (Memoirs,  Geological  Survey  of  India,  vol.  xxxi, 
p.  132);  but  it  should  be  remembered  that  no  striated  boulders  have  been  found  in  the 
Himalayas  or  in  the  Son  Valley. 

The  possibility  of  the  occurrence  of  a  representative  of  the  Blaini  boulder  slate  in  associ- 
ation with  the  fossiliferous  beds  of  Gurhwal  and  Kumaon  has  been  steadily  kept  in  view  dur- 
ing the  progress  of  geological  surveys  in  the  Himalaya,  and  it  may  be  assumed  that,  during 
his  survey,  Mr.  Griesbach  would  have  had  this  in  mind  when  studying  such  a  rock  as  the 
boulder-bed  that  he  describes,  and  would  have  been  on  the  lookout  for  evidences  of  glacial 


4»  RESEARCH   IN  CHINA. 

action.  The  same  bed,  however,  is  well  known  to  Mr.  C.  S.  Middlemiss,  who  had  the 
opportunity  of  visiting  many  of  the  sections  in  Mr.  Griesbach's  company.  Mr.  Middlemiss 
states  that  the  conglomerate  bears  no  resemblance  to  a  till,  the  matrix  being  a  quartzite. 
The  term  "boulder-bed"  has  been  applied  to  the  Haimanta  rock  merely  on  account  of  the 
presence  in  it  of  unusually  large  boulders. 

The  middle  and  upper  divisions  of  the  Haimantus  are  thus  characterized 
(pages  52  and  53) : 

The  purple  quartzites  and  conglomerates  are  in  all  sections  overlain  by  a  great 
thickness  of  bluish-gray  phyllites,  shales,  and  thicker  bedded  quartzites,  traversed  by  many 
quartz  veins.  Towards  the  upper  portion  of  it  reddish-brown  or  pink  quartz  shales  are 
intercalated.  *  *  *  The  only  fossil  traces  known  from  this  system  have  been  found 
in  shales  in  this  division.  None  of  these  organic  remains  are  more  than  traces.  They 
are:  crinoid?  stem  impressions;  bivalve?  casts  and  numerous  casts  of  Bellerophon  sp. 
The  latter  occur  both  in  the  purplish-pink  quartzite  and  in  the  shales  accompanying  it, 
and  rather  high  up  in  the  sequence  of  beds  of  this  division. 

In  all  the  central  Himalayan  sections  through  the  Haimantas,  from  the  Kali  river  to 
the  Spiti  province,  I  have  invariably  found  certain  beds  which  constitute  the  third  division. 
They  consist  of  two  zones  of  very  hard  quartz  shales,  the  lower  of  which  is  formed  by 
densely  red  and  pink  quartz  shales,  which  pass  upwards  into  greenish-gray  quartzite  and 
shales  with  pink  shaly  partings;  the  whole,  as  far  as  I  know,  quite  unfossilifcrous. 
Together  these  beds  are  not  more  than  250  to  500  feet  in  thickness. 

In  his  account  of  the  geology  of  Spiti  (page  13)  Hayden  discusses  dif- 
ferences of  observations  by  himself  and  Griesbach,  and  bases  his  conclu- 
sion upon  his  own  work,  which  in  that  region  was  the  more  thorough  of  the 
two.  He  fails  to  find  any  conglomerate  which  could  be  supposed  to  belong 
to  Griesbach's  lower  Haimanta  conglomerate,  except  in  one  instance  in 
which  the  rock  is  clearly  autoclastic.  This  difference  may  perhaps  find  its 
explanation  in  the  suggestion  of  a  glacial  origin  of  the  conglomerates,  since 
they  might  in  that  case  be  of  peculiarly  local  occurrence.  After  referring  to 
the  lower  beds  as  slates,  quartzites,  and  grits,  Hayden  proceeds  (page  13) : 

The  overlying  beds,  which  presumably  comprise  Mr.  Griesbach's  upper  Haimantas, 
consist  of  a  series  of  black,  purple,  and  gray  slates,  with  gray,  green,  and  red  quartzites. 
The  lower  part  of  the  series  is  chiefly  argillaceous  and  the  upper  mainly  siliceous.  *  *  * 
Among  the  argillaceous  beds  are  bands  of  an  intensely  black  carbonaceous  shale,  resem- 
bling the  carbonaceous  shales  of  Simla.  *  *  * 

In  the  Parahio  valley  the  upper  siliceous  beds  pass  up  gradually  into  a  series  of  gray 
and  green  micaceous  quartzites  and  thinly  foliated  slates  and  shales,  with  narrow  bands 
of  light-gray  dolomite. 

The  slates,  which  are  usually  dark  blue  or  black,  vary  in  composition  from  a  soft 
argillaceous  rock  to  a  hard  siliceous  variety  with  much  mica.  *  *  *  The  slates  are 
interbedded  with  great  irregularity  with  gray,  yellow,  or  whitish  quartzites  which  are 
almost  invariably  capped  by  a  narrow  band  of  either  calcareous  quartzite  or  dolomitic 
limestone  only  a  few  inches  in  thickness.  The  limestone,  which  is  gray  on  fresh  fracture, 
weathers  to  a  pinkish  or  brownish  red  and  is  again  overlaid  by  slates  which  are  at  first  argil- 


ORDOVICIAN   WARPING.  49 

laceous,  but  gradually  become  more  and  more  siliceous  till  they  pass  up  again  into  quartz- 
itcs.  This  alternation  continues  with  great  regularity  for  many  hundred  feet.  Towards 
the  top  of  the  scries  the  argillaceous  beds  give  place  to  light-colored  siliceous  slates  and 
thin-bedded  flaggy  quartzites,  with  bands  of  red  and  pink  dolomite,  which  latter  gradually 
increases  in  frequency  and  thickness  till  it  becomes  the  predominant  rock.  These  beds 
constitute  the  oldest  fossiliferous  series  hitherto  found  in  Spiti. 

After  the  statement  of  a  detailed  section,  which  comprises  1,188  feet, 
371  meters,  of  strata,  there  follows  the  account  of  the  fossils.  Near  the  base 
of  the  section,  in  a  hard  calcareous  and  micaceous  quartzite,  occur  numerous 
valves  of  a  small  brachiopod  resembling  Lingulella,  with  which  are  associated 
indeterminate  fragments  of  the  head  shields  of  a  trilobite.  About  400  feet, 
1 20  meters,  higher,  trilobite  remains  are  again  abundant  but  poorly  pre- 
served. One  hundred  and  sixty  feet,  48  meters,  still  higher  up,  large  num- 
bers of  specimens  were  collected  in  a  very  fair  state  of  preservation.  They 
are  said  to  consist  chiefly  of  species  of  Ptychoparia,  Cor  da,  and  allied  genera. 
A  hundred  feet,  30  meters,  higher  Ptychoparia  is  still  found  and  with  it  large 
numbers  of  fragments  of  Olenus  sp.  and  Dikelocephalus  sp.  About  90  feet, 
27  meters,  still  higher  occur  the  uppermost  determinable  fossils,  among 
which  Ptychoparia  is  rare  and  Olenus  common.  Although  the  collections 
which  are  thus  briefly  described  had  not  been  studied,  the  forms  recognized 
are  considered  sufficient  to  warrant  the  inference  that  the  fossiliferous  beds 
are  of  Upper,  possibly  also  of  Middle,  Cambrian  age. 

POST-S1NIAN  DIASTROPHISM. 

Sinian  strata  are  commonly  parallel  in  attitude  with  late  Paleozoic 
strata,  where  any  such  are  present.  The  areas  in  which  the  sequence  is 
apparently  immediate  and  sedimentation  was  continuous  are  limited,  so 
far  as  we  know,  to  Central  China;  those  strata  that  immediately  succeed 
are  distinctly  terrigenous  sediments,  which  contrast  decidedly  with  the 
underlying  marine  limestones  and  represent  a  revival  of  erosion.  Those 
areas  over  which  an  unconformity  of  erosion  without  discordance  exists 
are  extensive  and  comprise  the  Paleozoic  of  North  China. 

From  these  facts  it  follows  that  diastrophism  at  the  close  of  the  Sinian 
time  involved  broad  epeirogenic  changes,  without  marked  orogenic  disturb- 
ances, within  the  provinces  of  eastern  Asia. 

An  exact  date  of  the  movement  can  not  be  inferred  in  the  region  of 
unconformity  by  erosion,  for  it  is  impossible  to  determine  what  strata  may 
have  been  removed  from  the  latest  which  are  there  present  beneath  the 
unconformity.  The  latest  remaining  are  lower  Ordovician ;  they  are  over- 
lain by  upper  Carboniferous;  and  it  is  possible  that  Silurian,  Devonian,  or 
lower  Carboniferous  deposits  may  have  been  spread  over  the  area.  It 


50  RESEARCH    IN    CHINA. 

is  not,  however,  probable.     Had  such  later  strata  accumulated  to  notable 
thickness  over  the  several  hundred   thousand   square   miles   under  con- 
sideration, they  must  have  been  removed  before  the  upper  Carboniferous 
was  laid  down,  and  they  should  constitute  a  notable  terrigenous  formation 
between  the  Sinian  and  Wu-shan  limestones  in  the  region  of  continuous 
sedimentation.    The  Sin-t'an  shale  occupies  this  position,  and  it  is  but  1,800 
feet,  550  meters,  thick.     Considering  the  extent  of  the  lands  from  which 
the  sand  and  clay  were  derived,  the  volume  of  the  formation  represents 
a  comparatively  thin  sheet  of  material  eroded.     Further,  so  far  as  exten- 
sive, though  not  comprehensive,  observations  enable  us  to  judge,  the  level 
of  unconformity  does  not  vary  greatly  from  a  general  horizon  in  the  upper 
Sinian;   that  is,  the  limestone   remained   practically   flat   and   protected, 
was  ultimately  bared,  and  soon  after  was  covered  by  upper  Carboniferous. 
The  changes  of  condition  thus  indicated  are:  (i)  shallowing  of  the  sea,  such 
that  the  bottom,  on  which  limestone  had  been  accumulating,  was  scoured 
by  marine  currents;  (2)  after  an  indefinite  time,  gradual  exposure  of  the 
limestone  in  a  flat  coastal  plain,  where  at  any  one  time  a  narrow  belt  was 
subject  to  erosion;  and  (3)  progressive  deposition  of  littoral  or  continental 
sediments  upon  the  eroded  surface.     The  last  occurred  not  earlier  than 
middle  Carboniferous,  and  the  other  stages  cover  Devonian,  Silurian,  and 
upper  Ordovician.     It  is  possible  to  introduce  a  hypothetical  stage  of  depo- 
sition in  this  series  of  events,  between  i  and  2,  if  we  assume  that  the  deposit 
over  the  limestone  was  eroded  in  the  gradual  process  of  exposure;  it  is, 
indeed,  probable  that  a  thin  formation  of  terrigenous  character  accumulated 
as  a  temporary  storage  of  the  material  of  the  Sin-t'an  formation  in  its 
passage  from  the  crystalline  rocks  that  yielded  the  quartz  and  ferruginous 
clay;  but  there  is  no  direct  evidence  of  any  notable  marine  formation. 

The  date  of  inception  of  the  epeirogenic  movement  may  be  fixed  more 
nearly  in  the  region  of  continuous  sedimentation.  Transition  beds  of 
shale  and  limestone  follow  the  Sinian  limestone,  and  among  them  occurs 
a  stratum  which  contains  a  well-characterized  middle  Ordovician  (Trenton) 
fauna.  We  may  regard  these  transition  beds  as  marking  the  close  of  the 
general  marine  condition  and  the  beginning  of  the  period  of  little  or  no 
deposition.  In  contrast  to  the  areas  of  unconformity  by  erosion,  the  region 
of  conformable  deposits  presumably  remained  somewhat  deeply  submerged, 
was  not  subject  to  marine  scour  by  currents,  and  was  so  distant  from  the 
lowlands  of  the  time  that  it  received  but  little  sediment.  The  evidence 
of  this  appears  through  consideration  of  the  Middle  Paleozoic  strata. 

If  the  preceding  discussion  proves  trustworthy  a  very  interesting 
parallel  may  be  drawn  with  North  America.  The  Cambro-Ordovician 
transgression  there  closes  with  an  episode  marked  by  withdrawal  of  the 


A  GENERAL  GEOGRAPHIC  CHANGE.  51 

epicontinental  sea  from  extensive  areas  within  the  continent,  and  in  such 
wise  that  shallows  and  archipelagos  of  low  flat  islands  took  the  place  of 
wide  mediterraneans.  A  similar  physical  change  is  indicated  for  eastern 
Asia.  The  physical  history  of  both  continental  regions  was  one  of  pro- 
longed submergence,  favorable  to  cosmopolitan  evolution,  which  resulted 
in  the  development  of  related  faunas  in  the  two  areas;  and  the  withdrawal 
of  marine  waters  checked  the  faunal  variation  at  the  same  stage  on  opposite 
sides  of  the  globe.  The  geographic  change  was  not  occasioned  by  notable 
disturbances  of  the  continental  masses,  although  there  probably  was  some 
gentle  warping;  but  it  may  with  reason  be  ascribed  to  a  decided  deepening 
of  the  ocean  basins.  The  trend  of  the  evidence,  which  may  be  traced  more 
in  detail  in  America  and  Europe  than  at  present  in  Asia,  is  to  establish 
proof  of  a  general  lowering  of  the  sea-level,  such  a  change  as  Suess  desig- 
nates a  negative  eustatic  movement.*  The  world-wide  prevalence  of  the 
preceding  marine  transgression,  its  long  duration,  the  corresponding  devel- 
opment of  identical  life  conditions  and  consequently  of  closely  related 
organisms,  and  the  universality  of  the  sea-level  datum,  all  combine  to 
render  that  particular  negative  movement  one  of  the  most  definite  time 
records  in  geologic  history. 

*La  Face  de  la  Terre,  vol.  n,  p.  841. 


RESEARCH  IN   CHINA 


Southern  Asitt  ilurinq  the 


LEGEND 


QUATERNARY 

AND 

TERTIARY 
(Basins  deeply  filled  by 
continental  defxtsitsl 


SIMIAN    LANDS 
t  Areas  where  marine  deposits 
were  probably  notl 


CHAPTER  IV.— MIDDLE  PALEOZOIC. 


SILURO-DEVONIAN  STRATA  OF  CHINA. 

The  preceding  chapter  upon  the  Sinian  system  deals  with  the  stra- 
tigraphy of  the  Cambrian  and  lower  Ordovician  of  eastern  Asia.  Under 
the  division  middle  Paleozoic  I  propose  to  describe  the  strata  which  fall 
between  the  Sinian  and  the  Carboniferous,  comprising  those  assigned  to 
the  upper  Ordovician,  Silurian  or  Gothlandian,  and  Devonian. 

We  may  first  cite  the  early  observations  made  by  von  Richthofen, 
who,  in  his  second  excursion  into  the  geologically  unknown  China,  explored 
the  lower  Yang-tz'i,  particularly  between  Kiu-kiang  and  Nan-king.  The 
only  account  of  his  observations  that  I  have  yet  been  able  to  find  is 
contained  in  the  proceedings  of  the  American  Academy  of  Arts  and  Sciences, 
volume  viu,  May  26,  1869.  A  number  of  formations  are  distinguished  by 
local  names.  Of  these  the  first  four,  namely,  the  Ta-ho,  the  Lu-shan  schists, 
the  Matsu  limestone,  and  the  granite  intrusions,  elude  classification.  The 
fifth  in  von  Richthofen's  enumeration,  namely  the  Tung-ting  sandstone, 
is  also  of  uncertain  position,  but  was  supposed  by  him  to  extend  con- 
formably beneath  the  Devonian  limestone,  which  is  next  in  the  series. 
To  this  Devonian  representative  von  Richthofen  gave  the  name  of  Si-ho, 
and  he  says  of  it: 

This  is  a  limestone  formation  only  600  feet  in  thickness.  The  rock  is  full  of  chert 
nodules  and  contains  numerous  fossils,  chiefly  corals,  encrinites,  and  brachiopods.  Aulopora 
repens  is  of  frequent  occurrence  among  them,  and  other  forms,  too,  indicate  a  Devonian 
age.  The  name  is  derived  from  a  prominent  hill  generally  known  as  Single  Tree  Hill,  east 
of  Nan-king,  where  I  first  found  the  fossils. 

Seventh  in  the  series  named  by  von  Richthofen  are  the  Nan-king  grits, 
which  he  described  as  a  gritty  and  purely  quartzose  sandstone,  mostly  red 
but  variegated,  alternating  frequently  with  a  coarse  conglomerate  of  per- 
fectly rounded  pebbles  consisting  exclusively  of  quartz.  In  certain  dark 
shales  which  are  interstratified  occur  indeterminable  fossil  plants. 

Conformably  overlying  the  preceding  is  the  Carboniferous  limestone, 
called  Ki-tau,  a  name  which  takes  precedence  of  all  others  for  this  forma- 
tion in  China.  It  consists  of  three  members  in  this  locality,  namely  (i)  a 
lower  limestone  characterized  by  Fusulina  cylindrica,  1,400  feet,  420  meters; 
(2)  black  sandy  shales,  black  lydite,  and  soft  sandstone,  about  400  feet,  120 
meters,  thick,  containing  in  the  lower  strata  especially  large  specimens  of 

53 


54  RESEARCH   IN   CHINA. 

Productus  semireticulatus,  accompanied  by  numerous  other  brachiopods, 
bivalves,  corals,  and  fenestellas;  and  (3)  an  upper  limestone  more  than 
i, 600  feet,  480  meters,  thick,  which  is  separated  from  a  bed  of  coal  of  the 
preceding  member  only  by  a  thin  stratum  of  black  shale  and  is  similar  in 
nature  to  the  lower  limestone.  The  Ki-tau  corresponds  in  a  general  way 
with  the  Wu-shan  limestone. 

The  further  description  deals  with  beds  of  Mesozoic  and  later  age  which 
rest  unconformably  upon  the  Carboniferous. 

A  type  of  the  middle  Paleozoic  is  found  in  central  China,  in  eastern 
T  —  Ss'i-ch'uan,  southern  Sli^ii-si,  and  western  Hu-pei'.  The  region  is  moun- 
tainous, the  strata  are  folded,  and  exposures  are  practically  continuous  in 
the  superb  canyons  of  the  Yang-tzi-kiang  and  its  tributaries. 

Descriptions  of  supposed  Devonian  rocks  in  place  are  given  by  Pum- 
pelly  in  his  account  of  the  Yang-tzi  gorges.  The  great  limestone  which  rests 
on  the  pre-Cambrian  rocks,  and  is  now  known  to  be  of  Cambro-Ordovician 
age,  was  called  by  him  Devonian  on  the  supposition  that  the  fossils  of  that 
age  from  China  were  from  the  limestone  in  question.  In  fact,  Devonian 
in  that  region  is  either  absent  or  represented  by  the  shale  which  appears 
immediately  above  the  limestone  in  several  places  in  the  gorges  through 
which  Pumpelly  passed  in  his  adventurous  journey.* 

Sections  observed  by  our  expedition  occur  on  the  Ta-ning-ho,  longitude 
110°  east,  and  on  the  Yang-tzi'-kiang,  from  that  meridian  east  to  I-chang.f 
At  the  base  collections  of  middle  Ordovician  fossils  were  obtained  from  the 
transition  strata  of  the  Ki-sin-ling  limestone  near  Su-kia-pa,  a  village  on 
the  Ta-ning-ho  in  eastern  Ssi-ch'uan,  latitude  31°  40',  longitude  109°  40'. 
From  a  local  bed  at  the  top,  a  pink  limestone  near  Ta-miau-ssi',  we  obtained 
forms  which  may  be  Devonian  or  lower  Carboniferous. 

At  Su-kia-pa  the  middle  Paleozoic  strata  lie  in  a  closely  folded  syncline, 
with  nearly  vertical  dip  between  outcrops  of  the  underlying  Ki-sin-ling, 
(Sinian)  limestone.  The  sequence  is  continuous,  conformable,  and  appar- 
ently complex;  the  following  are  the  principal  rocks  in  order  from  the  top 
downward : 

Massive  gray  limestone,  with  abundant  black  chert  nodules  and  upper  Carboniferous 
fossils;  base  of  the  Wu-shan  limestone. 

Sandy  shale,  chiefly  green,  in  part  black;  calcareous,  ferruginous,  bituminous,  and 
coaly  near  the  top  ?  also  bituminous  and  black  200  to  300  feet,  60  to  90  meters, 
above  the  base;  weathers  earthy  brown  and  iron  stained:  total  1,800  feet,  550 
meters;  Silurian,  Devonian,  or  lower  Carboniferous  fossils  at  the  top. 

Gray  limestone,  200  feet,  60  meters. 


*  Smithsonian  Contributions    to    Knowledge,   vol.  xv,  Geological    Researches  in  China,   Mongolia, 
and  Japan,  during  the  years  1862-65,  R.  Pumpelly,  pages  5-6. 
•(•Vol.  i,  pp.  270-271;  atlas  sheets  d  6  and  d  7,  geology. 


MIDDLE   PALEOZOIC,    CENTRAL   CHINA.  55 

Black  chert,   "lydite";  a  characteristic  stratum  which  does  not,  however,  always 

occur  in  its  place;  checks  on  weathering  into  small  angular  fragments;  thickness 

5  feet,  1.5  meters. 
Green  shale  with  numerous  nodules  of  gray  to  brown  ferruginous  limestone:   100  feet, 

30  meters;  highly  fossiliferous,  middle  Ordovician  (Trenton)  fauna. 
I/ight-gray  to  bluish  limestone,  in  layers  2  to  6  inches  thick,  containing  Orthoceras  and 

coiled  gastropods,  lower  Ordovician ;  upper  part  of  the  Sinian  (Ki-sin-ling)  limestone. 

The  characteristic  green  shales  of  the  middle  Paleozoic  occur  in  typical 
development  on  the  Yang-tzi-kiang,  in  longitude  110°  45'  E.,  at  the  village 
of  Sin-t'an,  and  the  name  is  conveniently  used  to  designate  the  sequence  of 
strata  between  the  Ki-sin-ling  (Sinian)  limestone  below  and  the  Wu-shan 
(Carboniferous)  above.  Transition  beds  200  feet,  60  meters,  thick  connect 
the  Ki-sin-ling  and  Sin-t'an  and  are  characterized  by  upper  Ordovician 
fossils.  The  top  of  the  Sin-t'an  is  marked  by  a  distinct  but  conformable 
contact  of  shale  with  the  overlying  massive  Wu-shan  limestone. 

From  the  limits  stated  it  will  be  seen  that  the  Sin-t'an  formation  rep- 
resents all  of  Silurian  (Gothlandian) ,  Devonian,  and  lower  Carboniferous 
time.  Including  the  upper  Ordovician  transition  beds,  it  is  but  2,000  feet, 
600  meters,  thick,  and  as  a  whole  is  a  rather  monotonous  clayey,  sandy 
deposit,  modified  by  more  or  less  calcareous,  ferruginous,  or  bituminous 
admixture.  We  were  not  able  to  detect  any  evidence  of  unconformity  at 
the  base  or  top  of  the  formation,  nor  within  it.  We  regard  it  as  a  unit  in 
a  complete  sequence  of  strata;  but  it  was  evident  that  sedimentation  was 
meager  during  most  of  the  periods  represented.  While  it  is  possible  that 
the  deposit  accumulated  chiefly  during  some  particular  epoch,  we  have  no 
clue  to  that  one. 

The  fauna  found  in  the  limestone  nodules  in  green  shale,  and  in  light- 
gray  limestone  near  by  is  described  by  Weller  in  volume  ill  of  this  series. 
It  affords  a  sound  basis  for  correlation  with  the  Trenton  limestone  of  the 
United  States  and  the  Vaginoceras  limestone  of  the  Baltic,  the  relations 
being  closer  with  the  latter.  The  horizon  falls  in  the  middle  Ordovician. 

Although  we  repeatedly  crossed  the  strata  equivalent  to  this  fossilifer- 
ous bed,  both  north  and  south  of  Sii-kia-pa,  none  of  the  party  observed 
the  fossils  at  any  other  locality.  We  may  have  overlooked  them,  especially 
in  running  the  swift  current  of  the  Ta-ning-ho  and -Yang-tzi-kiang  in  boats, 
but  it  is  probable  that  the  fossiliferous  calcareous-,  nodules  in  the  green 
shale  are  of  occasional,  not  general,  occurrence.  Where  they  do  occur  the 
fossils  are  conspicuous. 

In  general  the  Sin-t'an  formation  is  apparently  unfossiliferous.  Its 
bituminous  phases  have  much  the  character  of  the  middle  Devonian  shales 
of  the  eastern  United  States,  and  where  green  and  sandy  it  suggests  the 
Chemung. 


56  RESEARCH   IN   CHINA. 

At  the  top,  in  a  pink  limestone,  Blackwelder  found  a  few  fossils  which 
Girty  and  Bassler  have  studied.*  They  are  not  able  to  agree  on  a  definite 
correlation,  but  state  that,  whereas  the  bryozoa  indicate  an  age  correspond- 
ing to  the  American  Mississippian,  the  brachiopods  do  not  resemble  any 
Mississippian  fauna,  and  if  they  stood  alone  would  lead  Girty  to  class  them 
as  possibly  Silurian  (Gothlandian) .  The  presumption  is  that  the  horizon 
is  at  least  late  Devonian  or  lower  Carboniferous,  but  if  so  the  fauna  is  unlike 
others  of  those  times  previously  collected  in  China. 

This  stratum  of  pink  limestone  lies  but  a  few  feet  below  the  Wu-shan 
limestone  and  1,500  feet,  450  meters,  below  a  thin  bed  of  anthracite,  next  to 
which  Blackwelder  collected  a  Chonetes  of  upper  Carboniferous  affinities. 

Silurian  and  Devonian  strata  in  central  China  were  first  described  by 
von  Richthofen,  who  came  upon  them  in  southwestern  Shen-si  and  northern 
Ssi'-ch'uan,  en  route  from  Han-chung-fu,  longitude  107°  12',  latitude  32°  50' 
to  Kuan-yuan -hien,  longitude  106°  15',  latitude  32°  20'.  They  there  form 
the  southernmost  ranges  of  the  Ts'in-ling-shan,  north  of  the  Red  Basin 
of  Ssi'-ch'uan,  and  are  intricately  folded  and  overthrust.  The  strata  are, 
however,  richly  fossiliferous,  and  have  consequently  been  well  identified. 

South  of  the  town  of  Ning-kiang-chou  von  Richthofen  crossed  an 
anticlinal  range,  overturned  toward  the  south,  from  which  he  obtained 
the  following  section. f  (The  strata  are  designated  in  the  accompanying 
figures  and  discussion  by  the  letters  /  to  e  in  ascending  order.) 

(/)  Limestone  alternating  with  other  strata,  namely,  gray,  splintery,  siliceous  lime- 
stone, 15  feet;  clay  shales;  lydite  conglomerate,  and  lydite  sandstone.  The  pebbles  of 
the  conglomerate  in  some  of  the  beds  are  much  rounded,  in  others  they  are  rounded  on  the 
corners,  and  in  still  others  they  are  quite  angular  and  sharp-edged.  The  sandstones  are 
practically  a  fine-grained  conglomerate  of  the  same  kind.  Thereupon  follow,  in  continu- 
ous alternation,  shales  and  limestones  in  groups  of  varying  thicknesses.  Characteristic 
are:  red  limestones,  red  calcareous  marls  which  break  up  in  friable  shaly  pieces,  and  also 
green,  somewhat  crystalline  limestone,  yellow  and  green  calcareous  marls,  etc. 

The  limestone  layers  are  full  of  well-preserved  fossils;  in  the  upper  parts  trilobites 
and  brachiopods  predominate  (among  them  Orthis  calligramma  and  Spirijer  radiatus) ;  in 
the  lower,  crinoid  stems  and  corals.  Dr.  Kayser  determines  the  age  as  middle  .Silurian 
approximately  equivalent  to  the  upper  Llandovery. 

Adjacent  to  the  exposures  of  /  and  underlying  that  terrane  in  the 
overturned  limb  of  the  anticline  comes  a  formation  k  and  others  in  sequence, 
as  follows: 

(k)  A  great  thickness  of  green  clay  shales,  with  occasional  thin  limestone  layers,  in 
which  brachiopods  occur. 


*Vol.  i,  pp.  273-274. 
t  China,  vol.  n,  p.  596. 


MIDDLE   PALEOZOIC,   SHEN-SI.  57 

(t)  Beds  of  limestone  which  contain  much  clay  shale ;  the  limestone  consists  almost 
entirely  of  corals  in  distinct,  very  well-preserved  individuals,  which  attain  more  than  one 
foot  in  diameter  and  are  separated  by  shaly  material.  Favosites  jorbesi,  Haly sites  catenu- 
larius,  several  kinds  of  Heliolites,  Cyathophyllum,Amplexus,  and  Aheolites  occur,  according 
to  the  determination  of  Lindstrom,  together  with  other  Silurian  forms.  Crinoids  are 
numerous,  brachiopods  and  Orthoceras  scarce.  Of  trilobites  I  did  not  find  any. 

(h)  Green  clay  shales,  which  are  distinguished  by  occasional  layers  full  of  nodules  of 
limestone  in  bedded  form.  When  weathered  these  are  recognized  as  the  remains  of  corals, 
which  belong  to  some  of  the  species  enumerated  in  i,  but  are  much  smaller.  Limestone 
layers  of  the  most  varied  character  and  coloring  are  interbedded  with  the  shales  and 
alternate  with  them,  now  in  thick  beds,  again  in  the  thinnest  layers.  The  number  of 
fossils  is  extraordinarily  great  in  this  easily  recognized  formation.  Every  calcareous  piece 
exhibits  organic  structure.  Together  with  the  corals  occur  innumerable  long  crinoid 
stems,  small  trilobites,  and  many  brachiopods,  especially  species  of  Orthis.  The  last 
occur  in  such  heaps  that  they  alone  constitute  single  limestone  beds.  According  to  the 
determination  of  Dr.  Kayser,  the  terranes  i  and  h  are  Upper  Silurian,  approximately 
equivalent  to  the  Wenlock. 

(g)  Gray  limestone  and  soft  gray  calcareous  marl,  which,  according  to  the  occurrence 
of  Airy  pa  reticularis,  is  Devonian. 

(/)  Strongly  bituminous  limestone  of  blackish  and  liver-brown  color,  which  is  without 
question  identical  with  the  Carboniferous  limestone. 

The  gray,  splintery  limestone  at  the  base  of  this  section  is  not  recog- 
nized by  von  Richthofen  as  representing  the  Sinian,  but  probably  is  of  the 
transition  beds,  which  follow  the  typical  limestone  of  that  system  on  the 
Ta-ning-ho.  As  von  Richthofen  had  not  distinguished  the  Sinian  from 
the  Carboniferous,  he  was  not  prepared  to  recognize  it  where  only  the  top 
appears  in  an  unfamiliar  stratum. 

The  lydite  conglomerate  corresponds  with  the  black  chert  bed  which 
occupies  a  similar  horizon  in  the  Ta-ning-ho  section,  and  the  fauna  collected 
by  von  Richthofen  from  the  beds  /  and  k,  and  described  by  Kayser,  is 
regarded  by  Weller  as  closely  related  to  that  which  we  obtained  at  Su-kia-pa. 

In  this  connection  it  is  desirable  also  to  mention  certain  fossils 
described  by  Martelli,*  collected  by  the  missionary  Giuseppe  Giraldi  in 
the  vicinity  of  "Lean-san,"  in  the  Ts'in-ling  mountains  of  southern  Shan- 
si,  f  I  have  not  been  able  to  find  the  locality  "Lean-san"  (which  may 
perhaps  be  transliterated  L/iang-shan,  Two  Mountains)  on  any  European 
or  Chinese  map  available,  but  it  can  not  be  far  from  the  section  observed 
by  von  Richthofen.  Weller  regards  the  fauna  collected  by  Father  Giraldi 
as  even  more  nearly  related  to  that  from  Sii-kia-pa  than  is  that  described 
by  Kayser. 

*Bol.  Soc.  Geol.  Ital.,  vol.  xx,  p.  295,  Fossili  del  Siluriano  Inferiore  dello  Schensi  (Cina),  Alessandro 
Martelli. 

t  Probably  the  same  as  Abbe  David's  Lean-chan,  described  by  Paul  Fischer  in  Bull,  de  la  Soc.  Ge'ol., 
Ser.  m,  vol.  n,  p.  408. 


58  RESEARCH   IN   CHINA. 

Von  Rich  thof  en's  section  includes  Silurian  (Gothlandian)  strata  as 
determined  by  abundant  fossils  (beds  i  and  K)  and  a  very  meager  repre- 
sentation of  the  Devonian  (bed  g).  The  expedition  of  1903-04  found  no 
certainly  Silurian  fossils  in  the  Ta-ning-ho  section.  lyoczy,  who  traversed 
the  Kia-ling-kiang  just  west  of  von  Richthofen's  locality,  passed  in  a 
boat  and  did  not  observe  the  Silurian;  but  at  a  point  somewhat  further 
north  he  obtained  a  definite  observation  of  the  occurrence  of  the  Devonian. 
The  locality  is  in  the  western  Ts'in-ling-shan,  in  the  province  of  Shen-si, 
at  the  village  of  Paj-suj-kiang  (Pai-shui-kiang,  White  Water  River)  .  Loczy 
described  the  occurrence  as  follows:* 

When  we  had  left  a  steep  terrace  [Talstufe]  our  way  entered  a  narrow  ravine,  in  which 
steep  limestone  walls  rose  on  both  sides  almost  to  Paj-suj-kiang.  In  this  gorge  the  limon- 
itic  sandstone,  and  the  clay  shale  which  is  associated  with  it,  is  repeatedly  exposed  wherever 
the  arches  of  the  anticlines  have  been  cut  through  by  the  action  of  the  river.  Above  the 
sandstone  occur  well-bedded,  thin,  limestone  layers,  and  above  these  the  thick  beds  of  the 
bituminous  limestone  extend  to  the  high  ragged  edge  of  the  ravine. 

In  the  marly  strata  between  the  dark-blue  limestone  layers  occur  numerous  petrified 
remains  of  shellfish,  such  as  corals,  crinoids,  brachiopods,  fenestellas,  and  also  great  heaps 
of  shells  of  a  large  form  of  mussel.  The  cross-sections  of  the  latter  remind  one  strikingly 
of  those  of  megalodonts.  In  the  material  which  was  here  collected  the  following  species 
were  determinable  : 

Spirifer,  cf.  canalifera  Valen.  Cypricardinia  lamellosa  Phill. 

Dielasma  (cf.  sacculus)  minimum  n.  sp.  Favosites  cervicornis  Goldf. 

Pentamerus  brevirostris  Phill.  Stromatopora  sp.  indet. 
Megalodon  (sp.)  v.  Pachydomus?  sp. 

In  Europe  these  forms  are  characteristic  of  the  Devonian  system.  The  thin  Devonian 
strata  pass  upward  gradually  into  a  thick  bituminous  limestone;  in  consequence  of  this 
relation,  because  of  its  extraordinary  thickness,  and  also  on  account  of  its  analogy  with 
the  strata  which  von  Richthofen  described  and  definitely  determined  to  be  Carboniferous, 
I  place  this  limestone  formation  in  that  system.  We  may  therefore  conclude,  from  the 
stratigraphic  relations  as  well  as  from  the  conditions  of  deposition,  that,  on  the  southern 
slope  of  the  Shi'-ta-shan,  the  Devonian  and  Carboniferous  occur  in  an  unbroken,  continuous 
sequence. 

Our  route  extended  about  14  kilometers  upon  the  strata  which  I  have  just  described; 
below  occurred  the  carbonaceous  sandstone  and  clay  shale;  above  that  bluish  limestone 
interbedded  with  black  chert,  in  the  marly  layers  of  which  occurred  the  Devonian  fossils, 
and  finally  uppermost  came  the  Carboniferous  limestone,  which,  with  a  thickness  of  about 
400  meters,  extended  to  the  tower-like  pinnacled  divides  and  ragged  cavernous  plateau  of 
the  Shi-ta-shan. 


In  the  paragraphs  preceding  the  above-quoted  description, 
gives  an  account  of  the  rocks  immediately  below  those  containing  the 
Devonian  fossils,  describing  them  as  gray  ferruginous  sandstones,  contain- 
ing pyrite  and  brown  iron  oxide  with  interbedded  threads  of  coal.  This 

*  Reise  des  Grafen  Sz£chenyi,  vol.  i,  p.  433. 


WESTWARD   TO   TIBET.  59 

description  agrees  with  that  of  certain  portions  of  the  Sin-t'an  formation 
observed  by  our  expedition  in  eastern  Ss'i-ch'uan,  and  the  position  of  the 
fossiliferous  limestone  corresponds  with  that  of  the  pink  limestone  in 
which,  near  Ta-miau-ssi,  Blackwelder  found  the  few  fossils  that  are  doubt- 
fully referred  by  Girty  to  the  Devonian  or  lower  Carboniferous. 

On  the  agreement  of  the  observations  of  von  Richthofen  and  Loczy 
and  ourselves,  we  may  conclude  that  throughout  northern  Ss'i-ch'uan  and 
southern  Shen-si  the  Devonian  is  represented  by  thin  strata  of  calcareous, 
marly,  bituminous  character,  which  nowhere  attain  very  great  thickness, 
which  may  in  fact  be  wanting  in  some  sections,  and  which  are  conformable 
to  the  Silurian  (Gothlandian)  below  and  the  Carboniferous  above. 

In  connection  with  the  occurrence  of  middle  Paleozoic  fossiliferous 
strata  in  the  western  Ts'in-ling-shan  it  is  desirable  to  consider  the  for- 
mations of  the  Hei-shui  series,  which  were  observed  by  our  expedition  in 
crossing  that  range  in  longitude  108°  and  which  are  tentatively  assigned  to 
the  period.  They  are  siliceous  argillites  of  greenish  and  reddish  tints,  which 
more  nearly  resemble  the  Sin-t'an  formation  than  any  other  that  we  know, 
and  appear  to  occur  as  it  does,  between  a  massive  limestone  below  and  a 
coal-bearing  limestone  above.  In  general  terms  the  stratigraphic  similarity 
between  this  sequence  and  that  of  the  Paleozoic  in  the  middle  Yang-tz'i 
region  is  such  that  we  have  little  doubt  in  classing  the  whole  as  also  Pale- 
ozoic and  the  slate  formation  as  middle  Paleozoic.  The  slates  include 
quartzite  and  conglomerate  at  the  base  and  appear  to  be  thicker  than 
their  supposed  equivalents  further  south.  We  regard  them,  therefore,  as 
a  nearer  shore  phase,  and  also  recognize  that  they  may  include  a  more 
complete  sequence  than  is  found  in  the  Sin-t'an. 

MIDDLE  PALEOZOIC  STRATA  BEYOND  CHINA. 

We  may  next  consider  the  distribution  of  Devonian  strata  in  northern 
and  western  Tibet,  as  determined  by  Obrutchov,  Mushketov,  Romanovski, 
Bogdanovitch,  and  Stoliczka. 

The  journey  of  Loczy,  otherwise  so  fruitful  in  geologic  details,  gives  no 
clue  to  the  occurrence  of  the  Devonian  in  the  ranges  of  northern  Tibet.  In 
justice  to  him  it  must  be  said  that  his  opportunities  for  observation  were 
limited  by  the  official  attitude  of  the  Chinese  authorities  and  the  conditions 
attending  the  expedition  to  which  he  was  attached.  Although  he  traveled 
during  four  months  within  a  short  distance  of  the  northern  base  of  the 
Nan-shan,  he  was  able  to  observe  the  rocks  in  place  only  in  two  locali- 
ties; in  the  vicinity  of  Kan-chou-fu  and  south  of  Su-chou.  He  describes 
strata  which  he  considers  to  be  early  Paleozoic,  but  which,  as  stated  on  a 
previous  page,  are  not  identified  by  fossils  and  probably  are  of  pre-Cambrian 


60  RESEARCH    IN   CHINA. 

age.  His  observations  are  described  in  the  twelfth  chapter,  volume  i, 
of  his  work,  on  pages  552  to  559,  but  need  not  here  be  further  considered. 

Obrutchov's  journeys  in  northern  Tibet  were  very  extended.  His 
observations  are  unfortunately  not  fully  available.  The  two  great  volumes, 
Central  Asia  and  Northern  China,  published  in  Russian,  are  in  effect  an 
orderly  transcription  of  his  field-notes,  from  which  it  is  difficult  to  obtain 
an  idea  of  geologic  relations.*  In  his  preface  Obrutchov  reserves  all  con- 
clusions for  a  third  volume,  which  is  not  yet  available.  He  has,  however, 
found  a  most  able  interpreter  in  Suess,  who  supplemented  the  data  found 
in  the  volumes  by  correspondence  with  the  author.  I  quote  from  him. 
The  region  referred  to  lies  in  the  heart  of  Asia,  south  of  the  Gobi  desert  and 
north  of  the  Tibetan  plateau,  between  latitudes  35°  and  40°  north,  and  on 
either  side  of  longitude  100°  east.  The  description  includes  an  account  of 
rocks  which  are  both  older  and  younger  than  middle  Paleozoic  and  in  this 
volume  are  systematically  discussed  elsewhere,  but  the  quotation  is  best 
given  as  a  whole. 

Suess  says:f 

The  width  of  the  Nan-shan,  between  the  northern  margin  of  the  Tsai-dam  and  the 
southern  margin  of  the  oasis  of  Kan-su,  is  equal  to  the  width  of  the  Alps  between  Biella 
and  Freiburg,  and  one  may  say  that  all  the  region  commonly  designated  under  the  name  of 
Nan-shan  corresponds  approximately  in  extent  to  the  Swiss  Alps.  The  great  height  of 
the  ranges  is  accompanied,  however,  by  a  relatively  even  more  striking  altitude  of  the 
valleys,  a  circumstance  which  diminishes  the  differences  of  level  in  the  interior  of  the 
mountainous  region,  but  the  observer  is  even  thus  below  the  limit  of  eternal  snow. 

From  Prevalsky  to  Roborovsky  numerous  but  hardy  observers  have  contributed  to 
knowledge  of  the  topography  of  this  mountainous  region,  but  up  to  the  present  time  only 
two  competent  geologists  have  traversed  it.  The  first  was  L6czy,  whose  researches  out- 
side of  the  northern  border  were  strictly  limited  to  the  route  from  Lan-chrtu  to  Liang-ch6u, 
to  the  valley  of  Si-ning  and  the  southeastern  part  of  the  country.  He  was  followed  by 
Obrutchov,  who  studied  several  sections  across  the  northern  ranges  and  in  a  long  expedi- 
tion traversed  all  the  chains  in  the  vicinity  of  their  northwestern  extremity.  Thence, 
following  their  direction,  he  reached  the  field  of  observation  of  L,6czy,  south  of  the  Ku-ku- 
nor,  and  thereafter,  crossing  the  eastern  part  of  the  ranges,  regained  the  oasis  of  Kan-su. 

After  commenting  on  the  reconnaissance  character  of  these  investiga- 
tions and  the  incompleteness  of  our  knowledge,  he  says:J 

In  the  meridian  of  Sii-ch6u  four  high  mountain  chains  rise  between  the  oasis  of 
Kan-su  and  the  longitudinal  valley  of  Ku-ku-nor.  They  are  uniformly  directed  west- 
northwest.  They  are:  the  Richthofen  range,  the  To-lai-shan,  the  range  of  Alexander  the 
Third,  and  a  fourth  chain  which  is  little  known  and  is  separated  from  the  preceding  by  a 

*  In  examining  these  volumes  I  have  been  greatly  assisted  by  Mr.  G.  Zon,  assistant  forester,  Bureau  of 
Forestry,  U.  S.  Department  of  Agriculture. 

|  La  Face  de  la  Terre,  French  edition,  1902;  vol.  in,  part  i,  page  231. 
%Ibid.,  page  232. 


OBRUTCHOV   ON   THE   NAN-SHAN.  6 1 

valley  of  the  Sou-lai-khe  [Su-lei-ho].*  In  the  continuation  of  the  Alexander  mountains 
to  the  west-northwest,  or  a  little  to  the  south  of  this  line,  rises  the  Ta-sioue-shan  [Ta-sue- 
shan,  Great  Snowy  Range]. 

The  Richthofen  range  is  50  to  60  versts  across  and  may  be  divided  into  several  groups 
of  folds,  of  which  the  first  without  doubt  exceeds  20,000  feet,  6,000  meters.  At  the  northern 
base,  near  Tsin-fo-sy,  southeast  of  Sou-tcheou  [Sii-chou],  there  is  a  mass  of  granite,  but 
although  the  granite  rises  rapidly  it  does  not  extend  far  into  the  mountains.  It  is  followed 
by  a  band  of  upper  Carboniferous  with  beds  of  coal,  inclined  to  the  southwest;  then  by 
lower  Carboniferous  with  Productus  striatus;  by  a  red  and  green  Devonian  sandstone; 
and  finally  by  quartzites  and  limestones  which  are  probably  Silurian.  Before  the  first 
summits  of  the  range  are  attained  the  beds  are  already  inclined  towards  the  north,  and  all 
the  ridges  of  the  Richthofen  range  may  be  considered  as  closely  appressed  folds  of  anal- 
ogous Paleozoic  terranes,  which  are  tilted  to  verticality  or  overturned  toward  the  south. 
There  seem  also  to  be  overthrusts.  Possibly  some  of  the  coal-measures  belong  to  the 
Angara  series.  At  the  southernmost  divide  called  the  Tsin-pin-ta-pan  (14,000  feet,  4,220 
meters)  and  even  above  this  pass  strata  of  the  Gobi  series  lie  in  discordance  against  the 
southern  base  of  the  Richthofen  mountains ;  they  everywhere  dip  very  steeply  toward  the 
valley  of  Khoun-tschoui,  which  forms  the  limit  of  the  slope  of  the  To-lai-shan.  *  *  * 

Still  further  to  the  west-northwest  on  the  middle  course  of  the  Sou-lai-khe  [Su-leii-ho] 
there  occur  in  the  Paleozoic  series  of  the  Richthofen  mountains  red  and  green  sandstones, 
in  the  midst  of  which  are  interbedded  layers  which  contain  Devonian  fossils  (Rhynchonella 
alinensis  according  to  Tschernyschew) .  Obrutchov  mentions  in  another  locality  Spirifer 
elegans  and  Spirifer  anosoffi.  [Central  Asia,  n,  pp.  9  and  10.] 

We  may  here  interpolate  an  extract  from  Obrutchov's  own  account  :f 

On  the  southern  slope  [of  the  Richthofen  range]  we  see  a  thick  series  of  supra- 
Carboniferous  deposits  forming  one  of  the  southern  ridges,  the  divide  of  the  range.  They 
strike  north-northwest  diagonally  to  the  range,  and  dip  steeply  on  both  sides.  Below  the 
peak  Yang-k'ou-er  appear  more  ancient  formations:  gray  sandstone  and  shales  slightly 
metamorphosed,  which  I  consider  ancient  Paleozoic.  They  do  not  resemble  closely  the 
ordinary  metamorphic  sandstone  and  schists  of  the  Nan-shan  and  other  parts  of  central 
Asia.  They  may  be  Silurian,  or  perhaps  still  older.  Fossils  have  not  been  found.  This 
series  is  much  contorted  in  various  directions,  east-northeast,  east-west,  and  west-north- 
west. Apparently  it  formed  the  range  when  the  supra-Carboniferous  sandstones  were 
deposited  at  its  southern  base ;  now  it  forms  the  southern  slope  of  the  main  ridge.  The 
remaining  part  of  the  Richthofen  range  represents  an  enormous  anticline,  which  is  over- 
turned southward,  and  on  the  limbs  is  composed  of  a  great  thickness,  2,800  to  3,500  feet, 
850  to  1,050  meters,  of  conglomerates,  mostly  of  red  color;  in  the  southern  limb  they  stand 
almost  perpendicular  and  in  the  northern  they  dip  inward.  Near  the  axis  of  the  fold  the 
conglomerates  are  replaced  by  red  and  green  sandstones  and  shales  with  thin  layers  of 
conglomerate.  These  strata  apparently  form  secondary  steep  folds.  The  strike  is  west- 
northwest,  parallel  to  the  modern  Richthofen  range,  as  might  be  expected,  since  the  range 
has  been  formed  in  its  present  position  by  the  dislocation  of  this  series.  The  thickness  of 
the  conglomerate  of  the  southern  limb  forms  the  crest  of  the  mountain  chain,  with  its 


*The  French  spelling  kh£  is  a  transcription  of  the  Russian  xe,  pronounced  as  xo,  and  rendered  in 
English  ho,  the  Chinese  for  river. 

t  Central  Asia,  North  China,  and  the  Nan-shan,  vol.  n,  p.  145. 


62  RESEARCH   IN   CHINA. 

steep  rocky  peaks.  The  series  of  red  conglomerates  underlain  with  red  and  green  sand- 
stone and  shales  is  most  probably  pre-Carboniferous.  I  think  it  equivalent  to  the  series 
of  red  and  green  sandstone  with  middle  Devonian  fossils,  which  I  have  found  in  the  Richt- 
hofen  range  considerably  further  west  on  the  section  from  the  spring  A-tza-k'ou  to  the 
oasis  Ch'ou-ma-er  (pages  8-10) ;  and  also  in  a  nearer  section,  in  the  canyon  of  Tsin-fo-ssi, 
east  of  the  meridian  of  Su  chou.  We  shall  meet  a  series  of  red  and  green  sandstones  and 
shales,  which  underlie  Carboniferous  limestones  with  fossils  and  which  form  the  northern 
ridges  of  the  range ;  a  similar  red  conglomerate  was  seen  in  the  eastern  part  of  the  range 
Mo-ma-shan.  Hence  it  is  more  probable  that  all  these  similar  formations  of  the  Richt- 
hofen  range  present  shore  and  shallow  water  deposits  of  the  same  age,  namely  Devonian. 

Suess  continues:* 

The  To-lai'-shan  in  the  meridian  of  Sou-tcheou  is  a  somewhat  narrow  chain,  but 
like  the  Richthofen  range,  rises  high  above  the  snow-line,  of  which  the  altitude  is  14,600  to 
15,200  feet,  4,400  to  4,600  meters,  in  this  region.  It  is  distinguished  from  the  preceding 
range  by  an  outcrop  of  gneiss  along  its  southern  border.  The  attitude  of  the  beds,  accord- 
ing to  the  description  of  Obrutchov,  is  very  peculiar:  after  having  crossed,  in  coming 
from  the  north,  the  intermontane  belt  of  the  deposits  of  Gobi,  one  observes  intense  folding 
in  a  Paleozoic  series,  which  is  very  thick.  Locally  the  strike  is  northeast  or  north-northeast ; 
then  the  strata  resume  the  dominant  west-northwest  orientation,  and  finally  the  most 
recent  formations,  the  Carboniferous  with  beds  of  coal  and  Fusulina  limestone,  rest  upon 
the  gneiss.  The  impression  which  the  section  gives  in  this  locality  is  indeed  not  so  much 
that  there  is  an  overlap  of  the  upper  Carboniferous  upon  the  gneiss  as  that  there  is  an 
overthrust  toward  the  south,  of  the  entire  Paleozoic  series  upon  the  gneissic  belt. 

Referring  to  another  section  of  the  To-lai'-shan,  about  50  versts,  53 
kilometers,  west-northwest  of  the  firstf  Suess  describes  the  continuation  of 
the  folds  which  involve  Devonian  and  later  Paleozoic  strata  resting  upon 
raetaraorphic  schists;  and  shows  further  that  the  gneissoid  zone  along  the 
southern  margin,  which  has  widened  considerably,  appears  to  be  underlain 
both  north  and  south  by  upper  Carboniferous  coal-measures.  This  struc- 
ture presents  a  problem  of  overlap  or  overthrust  which  remains  indeter- 
minate. 

The  range  of  Alexander  the  Third  rises  south  of  the  broad  valley  of  To-lai-kouan, 
which  is  entirely  filled  with  debris ;  it  is  formed,  as  may  be  seen  from  two  transverse 
sections  taken  a  score  of  versts  apart,  of  lower  Paleozoic  strata  upturned  and  folded. 
Toward  the  south  these  beds  pass  beneath  a  great  syncline  of  Carboniferous  strata,  in 
the  midst  of  which  the  sandstones  above  the  coal-measures  are  very  extensively  developed. 
This  synclinorium  is  so  broad  that  the  sandstones  overlying  the  coal-measures  constitute  a 
series  of  secondary  arches,  and  the  summits  of  the  Ou-jd-chan,  the  most  elevated  part 
of  the  chain,  probably  consist  of  them.$ 

Obrutchov  himself  sums  up  his  description  of  the  section  of  the  range 
of  Alexander  the  Third  by  saying  that  "To-day's  observations  show  that 

*La  Face  de  la  Terre,  vol.  in,  p.  234. 
f  Ibid.,  bottom  of  page  235. 
%Ibid.,  page  236. 


THE   WESTERN  KUEN-LUNG.  63 

the  series  of  gray  schists,  quartzites,  and  limestones,  is  considered  older 
than  that  of  gray,  green,  and  lilac  shales,  which  we  take  for  Devonian." 

These  older  schists,  quartzites,  and  limestones  belong  to  that  series 
which  has  been  considered  early  Paleozoic,  but  which  I  correlate  tentatively 
with  the  late  Proterozoic.  I  shall  refer  to  it  again  in  connection  with  Pale- 
ozoic diastrophism. 

Having  referred  briefly  to  the  structure  of  the  fourth  chain,  which  is 
but  imperfectly  known,  but  which  is  undoubtedly  formed  by  beds  of 
Paleozoic  strata,  in  part  at  least,  Suess  proceeds:* 

The  structure  of  these  four  ranges  of  the  Nan-shan,  from  the  oasis  of  Kan-su  to  the 
vicinity  of  the  valley  of  Bouk-hai'n-gol  thus  presents  the  following  characteristics:  gneiss 
is  seen  only  upon  the  southern  flank  of  the  To-lai'-shan;  all  the  rest  of  the  mountainous 
region  is  formed  of  closely  folded  Paleozoic  sediments.  Near  the  northern  margin  there 
are  suggestions  of  an  overturn  toward  the  north ;  in  the  interior  of  the  mountains  the  beds 
appear  in  a  vertical  position  or  exhibit  a  movement  toward  the  south.  The  gneissic  zone 
is  not  associated  with  the  lowest  strata  of  the  Paleozoic  series,  as  would  be  expected  in  the 
normal  succession,  but  instead  with  the  Upper  Carboniferous. 

The  observations  of  Obrutchov  in  the  southeastern  portion  of  the  Nan- 
shan,  as  quoted  by  Suess,  show  that  the  pre-Carboniferous  Paleozoic  strata 
are  present  in  that  part  of  the  range.  There  can  be  no  question  but  that 
outcrops  of  Devonian  strata  extend  from  the  vicinity  of  Lan-chou  south- 
eastward along  the  trend  of  the  mountain  chains  to  southwestern  Shen-si, 
in  the  region  where  Loczy  collected  fossils  of  that  period  near  Paj-suj-kiang. 

Proceeding  westward  from  the  Nan-shan  range,  along  the  southern 
margin  of  the  Gobi,  we  have  in  the  western  Kuen-lung  a  section  by  Bog- 
danovitch  across  the  ranges  adjacent  to  what  is  known  as  the  Valley  of  the 
Winds.  I  again  quote  Suess  :f 

One  of  the  sections  which  Bogdanovitch  observed  across  the  western  Kuen-lung 
crosses  the  Valley  of  the  Winds.  Coming  from  the  north  the  first  chain,  the  Altyn-tagh, 
is  formed  of  Devonian  with  masses  of  granite,  exactly  as  in  the  Russian  range  which  lies 
far  to  the  southwest.  The  second  chain,  the  Youssoup-alyk-tagh,  which  follows  the  Tchi- 
men-tagh,  is  a  broad  band  of  gneiss.  The  Valley  of  the  Winds  corresponds  to  a  Carbon- 
iferous syncline.  This  section,  which  somewhat  further  west  is  extended  southward,  first 
comes  to  the  opposite  limb  of  the  syncline,  then  to  the  steeply  inclined  Devonian  and  the 
great  granite  massif  of  the  Kyzyl-oungouin-in-tioure,  beyond  which  there  succeed  further 
outcrops  of  Devonian  strata.  It  is  in  the  region  beyond  this  massif  that  there  rises  the 
Ailik-tagh,  where  Bogdanovitch  found  at  a  great  altitude  "polypiers"  of  middle  Devonian 
age.J 


*La  Face  de  la  Terre,  vol.  in,  page  237. 
]lbid.,  page  243. 

JSee  also  Beitrage  zur  Stratigraphie  Zentral  Asiens,  Suess  in  Denkschriften  der  k.  Acad.  der  Wiss., 
Wien,  LXI,  1894,  p.  435. 


64  RESEARCH   IN   CHINA. 

Devonian  strata  are  known  where  the  Kuen-lung  converges  in  the 
Mustagata,  toward  the  Tien-shan,  and  have  been  identified  in  the  southern 
ranges  of  that  great  system,  north  of  the  Taklamakan  desert.  Farther  to 
the  northeast,  in  Trans-Baikalia,  they  constitute  the  oldest  fossiliferous 
rocks  known. 

We  have  thus  traced  the  repeated  outcrops  of  middle  Paleozoic  strata 
from  the  province  of  Shen-si  in  central  China,  in  longitude  106°  east  of 
Greenwich,  northwest  and  west  to  longitude  74°.  The  terranes  probably 
comprise  pre-Devonian  Paleozoics,  at  least  as  far  west  as  longitude  94°, 
but  in  the  section  last  quoted  from  Bogdanovitch  middle  Devonian  appears 
to  rest  directly  upon  the  crystallines.  Nevertheless,  in  the  present  state  of 
geologic  knowledge  of  these  remote  regions,  it  would  be  hazardous  to  assert 
that  earlier  Paleozoic,  even  to  Ordovician  or  Cambrian,  is  not  represented. 
Somewhat  farther  west,  in  the  Zaravchan  (Sarawschan)  range,  longitude 
70°,  Romanovski  collected  Halysiles  catenulatus.  The  middle  Paleozoic 
of  eastern  Turkestan  is  closely  related  to  and  connected  with  that  of 
Europe  by  way  of  the  Urals,  and  also  with  North  America  by  Siberia.* 

The  line  of  observations  which  we  have  followed  from  Central  China 
pursues  the  course  of  one  of  the  great  mountain  trends  of  Asia,  between  the 
Gobi  and  the  Tibetan  masses.  Paleozoic  strata  may  probably  be  absent 
over  part  of  the  latter,  at  least  if  the  inference  based  on  structural  axes  be 
valid.  Around  its  eastern  end  the  ranges  extend  southward  toward  the 
Malay  peninsula,  and  in  Burmah  they  are  joined  by  the  Himalaya  trends.f 
We  may  trace  the  occurrence  of  Middle  Paleozoic  rocks  along  this  southern 
route  also. 

Devonian  is  known  from  several  localities  in  southwestern  Ssi'-ch'uan 
and  adjacent  districts  in  Yun-nan,  among  the  Paleozoic  strata  which  form 
the  mountain  ranges  of  western  Tibet,  bordering  the  Mesozoic  red  basin 
on  the  west.  Westward  from  Ja-chou-fu  (latitude  30°,  longitude  103°) ,  in 
the  vicinity  of  "Lin-tschin-shien,"  Loczy  found  the  Jurassic  itself  thrown 
into  folds,  resting  unconformably  on  strata  which  he  assigns  in  general 
terms  to  Silurian,  i.  e.,  early  Paleozoic.  He  refers  to  the  rocks  simply  as 
limestone,  and  makes  the  correlation  without  paleontologic  evidence. % 
Beneath  these  strata  occur  granite  and  diabase.  A  few  miles  further 
west,  between  the  Fu-yung-ho  and  the  village  of  Hoani-pu  (Hua-ling-pu) 
he  crossed  the  Ta-shian-ling,  which  is  composed  of  granite  and  quartz 
porphyry  and  flanked  on  both  sides  by  coal-bearing  Jurassic  strata.  On 
the  northeastern  slope  the  supposed  Silurian  beds  occur.  The  town  of 

*De  Lapparent:  Trait6  de  Geologic,  1906,  vol.  n,  p.  864. 
fSuess:  La  Face  de  la  Terre,  vol.  in,  map. 
JReise  des  Grafen  Szechenyi,  vol.  i,  p.  677. 


DEVONIAN  OF   THE  SOUTH.  65 

Ni-tou,  a  short  distance  to  the  northwest,  lies  in  a  synclinal  basin  of  early 
Paleozoic  strata  overlain  by  Rhaetic  and  Jurassic  and  flanked  by  ranges 
of  granite  and  quartz  porphyry.  In  this  vicinity,  at  the  village  of  Hua- 
ling-pu,  Loczy  observed  closely  folded  shales  and  dark,  bituminous,  earthy 
limestones,  from  which  he  collected  a  number  of  fossils  of  middle  Devonian 
age.*  The  fossiliferous  limestone  beds  were  thin  and  apparently  under- 
lain by  sandy  shales  and  gray,  half-crystalline  limestones,  and  the  presence 
of  Silurian  strata  beneath  the  Devonian  was  observed. 

While  the  fossils  collected  in  this  locality  leave  no  question  of  the  pres- 
ence of  Devonian  strata,  the  relations  which  appear  to  be  implied  in  the 
accompanying  diagrams,  between  the  Paleozoics  and  the  adjacent  granites, 
are  not  at  all  clear.  One  would  infer  that  the  granites  were  pre-Paleozoic; 
on  the  other  hand  the  descriptions  suggest  that  they  may  be  intrusives 
and  of  post-Paleozoic  age. 

In  northern  Yun-nan,  in  latitude  28°,  longitude  104°,  is  the  celebrated 
locality  of  Ta-kuan-ting,  from  which  von  Richthofen  obtained  the  rich 
collection  described  by  Kayser.f  Von  Richthofen  did  not  himself  collect 
the  fossils,  but  purchased  them  in  the  province  of  Ss'i-ch'uan,  whither  they 
are  brought  in  great  numbers  as  medicinal  charms. 

I/a  Touche  and  Datta  determined  the  presence  of  Devonian  strata  in 
the  northern  Shan  states,  where  they  found  a  full  and  characteristic  fauna. 
The  presence  of  the  Silurian  rocks  is  probable,  but  not  determined.  J 

The  most  recent  and  complete  account  of  the  Ordovician  and  Silurian 
and  Devonian  in  the  Himalayas  is  that  given  by  Hayden.§  He  describes 
650  feet,  195  meters,  of  strata,  comprising  shaly  sandstones  at  the  base 
(150  feet,  45  meters),  shaly,  dolomitic,  and  siliceous  limestones  (420  feet,  125 
meters)  among  which  six  divisions  are  distinguished,  and  reddish  quartz- 
ite  (80  feet,  24  meters);  the  last  is  followed  by  the  unfossiliferous  white 
Muth  quartzite.  The  strata  have  yielded  fossils  ranging  from  Caradoc  to 
Llandovery  or  Wenlock,  and  therefore  corresponding  in  general  position 
with  the  beds  of  middle  Ordovician  and  Silurian  age  in  central  China.  The 
white  Muth  quartzite  passes  upward  into  siliceous  limestone,  which  is  con- 
sidered to  be  Devonian,  and  Devonian  strata  are  probably  present  through- 
out the  Himalayas,  although  of  very  moderate  thickness.  The  western 
extension  of  this  series  along  the  ranges  of  western  Asia  to  the  Caucasus  is 
not  clearly  made  out,  but  is  most  probable.  || 

*Reise  des  Grafen  Szechenyi,  vol.  I,  p.  682. 

t  China,  vol.  iv,  p.  76. 

JNoetling:  Gen.  Report  G.  S.  I.,  1900. 

§  Memoirs  G.  S.  I.,  vol.  xxxvi,  part  I,  pp.  24-27,  1904. 

II  De  Lapparent:  Traite  de  Gdologie,  1906,  vol.  n,  p.  812. 


66  RESEARCH   IN  CHINA. 

These  notes  suffice  to  trace  the  marine  connection  of  Central  China 
with  Europe  by  a  route  south  of  the  Tibetan  plateau  region,  and  thus  to 
bring  out  the  fact  that  the  interior  sea  of  Asia,  the  Tethys,  during  middle 
Paleozoic  time  completely  surrounded  the  plateau  region,  which  was  prob- 
ably a  land  area. 

MIDDLE  PALEOZOIC  DIASTROPHISM. 

Diastrophic  movements  in  China  during  the  middle  Paleozoic  were 
very  slight.  As  has  been  brought  out  in  discussing  the  sedimentation 
of  the  Silurian  and  Devonian  periods,  there  was  no  considerable  deposition 
of  marine  sediment,  no  evident  accumulation  of  continental  deposits,  no 
notable  depth  of  erosion.  A  stable  condition  of  the  southeastern  conti- 
nental masses  is  plainly  indicated. 

A  similar  inference  holds  for  Gondwana  Land  in  the  peninsula  of  India 
and  the  Tibetan  mass,  so  far  as  we  may  draw  one  from  the  meager  sedi- 
mentation that  represents  Silurian  (Gothlandian)  and  Devonian  in  the 
Himalayas :  a  few  hundred  feet  of  limestone  and  quartzite ;  the  lands  were 
not  high. 

A  somewhat  different  suggestion  lies  in  the  Devonian  and  Silurian  (?) 
deposits  of  northern  Tibet,  which  Obrutchov,  the  explorer  of  the  Nan-shan 
system,  describes  as  quartzites  and  shales  of  great  thickness.  They  appear 
to  represent  an  epoch  of  vigorous  denudation,  and  their  volume  seems  to 
stand  for  an  elevation  equivalent  to  a  mountain  range.  According  to 
Bogdanovitch,  there  is  an  overlap  of  middle  and  upper  Devonian  onto 
an  eroded  surface  which  exposes  granite;  the  elevation  had,  therefore,  by 
middle  Devonian  time,  given  place  to  peneplanation  and  subsidence;  he 
regards  this  invasion  of  the  sea  as  an  event  of  prime  importance  and 
designates  it  the  Kuen-lung  transgression. 

It  is  not  clear  what  the  nature  of  the  elevation  was:  an  orogenic 
movement,  perhaps  accompanied  by  granitic  intrusion,  or  an  upwarp 
without  folding  or  visible  intrusion?  Comparison  with  the  Taconic  dis- 
turbance in  New  England  or  the  Caledonian  movement  in  Scotland,  both 
during  Silurian  time,  tempts  speculation  to  postulate  a  similar  orogenic 
event  in  central  Asia;  but  the  conservative  position  taken  by  Suess*  in 
deferring  a  correlation  of  these  events  is  the  sound  one  in  the  limited  state 
of  knowledge.  This  attitude  is  the  more  reasonable  because  the  Taconic 
and  Caledonian  disturbances  are  geographically  and  presumably  causally 
related  to  the  Atlantic  basin,  whereas  the  region  in  central  Asia  belongs  to 
a  distinct  continental  province. 

*Beitrage  zur  Stratigraphie  Zentral  Asiens,  in  Denkschriften  der  k.  Akad.  Wiss.,  LXI,  1894,  P-  435- 


AN   UNCONFORMITY   BY   EROSION.  67 

PRE-CARBON1FEROUS  UNCONFORMITY. 

Throughout  northeastern  China,  in  the  provinces  of  Chi-li,  Shan-si, 
Shan-tung,  and  Ho-nan,  there  is  an  unconformity  which  brings  the  Ordo- 
vician  in  contact  with  the  Carboniferous.  Wherever  it  has  been  seen  the 
underlying  terrane  consists  of  the  upper  Sinian  (lower  Ordovician)  lime- 
stone; whereas  the  overlying  strata  are  shales  which  lie  a  hundred  feet  or 
so  below  beds  that  carry  upper  Carboniferous  fossils,  either  marine  shells 
or  plant  remains.  The  hiatus  appears,  therefore,  to  represent  later  Ordovi- 
cian, Silurian,  Devonian,  and  lower  Carboniferous  times. 

Local  observations  all  agree  that  the  Ordovician  and  Carboniferous 
strata  are  strictly  conformable ;  so  closely  parallel  are  they  that  von  Richt- 
hofen,  who  repeatedly  saw  the  contact,  assumed  that  they  formed  an 
unbroken  sequence,  and  characterized  the  Sinian  limestone  as  Kohlenkalk. 
He  did  not  find  any  of  the  sparsely  distributed  fossils,  by  which  its  age  has 
since  been  determined  by  Lorenz  and  ourselves,  and  his  error  is  one  which 
sprang  naturally  from  the  fact  that  he  had  previously  observed  a  massive 
Carboniferous  limestone  in  South  China.  It  follows  from  the  conformity 
of  dip  over  several  hundred  square  miles  that  the  region  in  question  was  not 
subjected  to  disturbing  influences  during  the  periods  represented.  The 
Sinian  strata  were  not  folded;  neither,  during  all  this  time,  were  they  raised 
to  an  elevation  at  which  they  might  have  been  deeply  eroded. 

Apart  from  the  fact  that  the  strata  above  and  below  the  plane  of 
unconformity  are  identified  by  fossils  and  the  existence  of  a  hiatus  is  thus 
proved,  the  contact  itself  shows  evidences  of  erosion.  The  Sinian  limestone 
is  deeply  fissured  and  cavernous.  The  cavities  show  waterworn  or  corroded 
surfaces,  commonly  found  in  limestones  exposed  to  meteoric  waters.  These 
cavities  are  filled  with  bright-colored  clays,  which  owe  their  varied  hues  to 
the  oxidation  and  hydration  of  the  iron  which  they  contain.  Bog-iron  ore, 
sufficient  in  quantity  to  be  mined,  and  calcareous  tufa  are  found  at  the 
contacts. 

The  significance  of  these  facts  has  been  discussed  in  connection  with  the 
consideration  of  post-Sinian  diastrophism.  For  detailed  descriptions  of  the 
unconformity  as  we  saw  it,  reference  may  be  made  to  volume  i,  pages  48 
and  147.  In  describing  the  coal-field  of  Po-shan  in  northern  Shan-tung, 
von  Richthofen*  states  with  reference  to  the  Kohlenkalk  (Sinian  lime- 
stone) that  he  found  no  fossils,  but  noted  that  in  contrast  to  similar  lime- 
stones in  other  regions  it  contained  no  chert.  This  distinction  is  one  in 
which  the  Sinian  differs  from  the  Carboniferous  limestone  of  southern 
China. 


*China,  Vol.  11,  p.  203. 


68  RESEARCH   IN  CHINA. 

He  then  proceeds : 

There  follow,  in  a  relation  which  I  am  not  able  to  determine  clearly,  but  apparently 
conformably,  a  series  of  deposits  which  begin  with  bright-colored  clays.  They  are  in 
part  stratified,  in  part  without  recognizable  structure,  and  fill  inequalities  in  the  eroded 
dolomite. 

Farther  north,  in  the  province  of  Liau-tung,  von  Richthofen  describes 
the  sequence  in  the  coal-field  of  T'ai-p'ing,*  and  gives  the  following  section: 

Limestone,  which  is  heavily  bedded  and  characterized  by  yellow  markings  that  resem- 
ble corals  but  are  indistinct  in  outline  on  the  kidney-brown  background,  and  which  does 
not  contain  flint,  is  followed  by  yellow  dolomitic  limestone,  thin-bedded  yellow  dolomite 
with  limonite,  red  ferruginous  clays  with  kidneys  and  nodules  of  hematite  and  limonite, 
white  sandstone,  and  coal. 

On  the  margin  of  the  great  coal-field  of  southeastern  Shan-si  the 
explorer  ascended  from  Hwai-king-fu  to  the  coal-measure  plateau  and 
observed  the  contact  of  the  coal-bearing  T'ai-yang  series  with  an  underlying 
limestone  in  the  type  locality.  He  says  :f 

Coal  and  iron  district  of  T'ai-yang.  Throughout  a  long  distance  on  the  west  side  of 
the  Pi-lo-shan  the  loess  hides  the  strata  above  the  limestone ;  but  before  one  reaches  T'ai- 
yang  one  has  opportunity  to  see  them  in  beautiful  exposures,  for  there  the  firm  rock  forms 
a  flat  ridge  which  connects  the  limestone  range  with  the  mountains  that  rise  further  west. 
They  consist  of  an  alternation  of  sandstone,  bright  clays,  yellow  dolomite,  rauchwacke, 
and  limestone  with  flint  nodules.  I  was  particularly  struck  with  the  analogy  of  the  system 
in  this  region  with  that  which  occurs  at  Po-shan-hie"n  in  Shan-tung,  between  the  limestone 
and  the  coal-bearing  sandstone.  Here,  as  well  as  there,  the  clays  are  used  for  making 
pottery.  In  both  localities  the  iron  ores  are  related  to  the  dolomites.  They  do  not,  how- 
ever, occur  interbedded  with  them,  as  indeed  the  rocks  of  this  horizon  are  in  general  not 
clearly  stratified,  but  exhibit  the  most  striking  irregularities  in  short  distances.  Here  the 
surface  of  the  dolomite  is  full  of  caverns  without  order,  and  in  these  the  iron  ores  are 
especially  common. 

The  figures  on  page  410  of  the  volume  illustrate  the  observed  relations 
between  the  coal-measures  and  the  underlying  limestone,  and  show  the  two 
to  be  conformable  in  dip  except  in  one  locality,  figure  86,  which  is,  however, 
not  described  in  the  text. 

The  observations  which  von  Richthofen  may  have  made  in  the  course 
of  his  journey  from  Canton  to  Han-kow  have  unfortunately  not  been 
published.  He  crossed  the  extensive  coal-fields  of  Hunan  and  particularly 
examined  that  on  the  Lui-ho,  a  branch  of  the  great  Hsiang-kiang,  which 
flows  into  Tung-ting  lake.  From  the  fact  that  coal-measure  plants  occur  in 
abundance  t  we  infer  that  the  Carboniferous  strata  resemble  those  of  the 


*  China,  vol.  n,  p.  287. 
t/Wrf.,  vol.  n,  p.  411. 
t  Ibid.,  vol.  i,  p.  xxxn. 


EXTENT  OF  THE   UNCONFORMITY.  69 

northern  provinces  in  being  of  continental  rather  than  marine  character. 
As  the  Carboniferous  limestone  occurs  in  the  region  to  the  northwest  and 
west,  and  also  to  the  east  between  Kiu-kiang  and  Nan-king,  Hu-nan 
appears  to  represent  a  peninsula  extending  southwestward  into  the  southern 
sea.  It  is  probable  that  the  unconformity  which  defines  the  northern  land 
areas  may  have  extended  thus  far  south. 

The  land  area  which  is  indicated  by  this  marked  unconformity  was 
probably  a  southeastern  extension  of  the  continental  area  which  existed  in 
Mongolia  and  central  Asia.  We  turn  naturally  to  the  observations  of  Loczy 
in  his  journey  from  Si-an-fu  to  Lan-ch6u-fu,  to  ascertain  the  conditions  at 
the  base  of  the  Carboniferous  in  the  province  of  Kan-su,  but  unfortunately  his 
route  over  the  loess  plateau  avoided  the  exposures  which  are  to  be  found  only 
in  the  deeper  canyons,  and  he  did  not  see  the  base  of  the  Carboniferous. 
The  section  of  the  Lo-pan-shan*  is  the  only  one  which  may  have  bearing 
upon  the  unconformity  in  question.  The  exact  locality  is  west  of  Pa-liang- 
fu,  near  longitude  106°,  latitude  35°  30'.  He  describes  a  limestone,  which 
he  calls  Kohlenkalk,  but  which  may  be  upper  Sinian,  as  being  unconform- 
ably  overlain  by  bright-colored  sandstones,  marbles,  and  conglomerates, 
which  he  assigns  to  the  Ober-Karbon,  i.  e.,  Permian.  If  the  underlying 
limestone  is  indeed  the  Carboniferous,  the  base  of  that  system  is  not  seen. 
If,  on  the  other  hand,  it  be  the  Sinian,  the  Carboniferous  is  wanting  and  is 
here  overlapped  by  the  Permian. 

*Reise  des  Grafen  Sz£chenyi,  vol.  i,  p.  486. 


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AND 

TERTIARY 
Hasi,Ls  deeply  filled  In- 
continental  <tt>/  H  's-it.v  i 


MIDDLE  PALEOZOIC  STRATA 


MIDDLE  PALEOZOIC  LANDS 

fArrux  ir/n'/v  tntirj/ie  tienavite 

were  firohtihlv  not  Utia  t/tm"n  I 


CHAPTER  V.— LATE  PALEOZOIC. 


CARBONIFEROUS  STRATA. 

The  Carboniferous  strata  of  China  constitute  two  very  distinct  series, 
both  of  which  are,  however,  apparently  of  upper  Carboniferous  (Pennsyl- 
vanian)  age.  The  one  is  a  sequence  of  essentially  continental  deposits: 
sandstone  and  shales,  with  numerous  coal-beds  and  occasional  thin  bitu- 
minous limestones.  Many  of  these  strata  are  no  doubt  marine,  the  lime- 
stones in  particular  being  characterized  by  marine  fossils;  but  many  others 
belong  to  a  coastal  plain  and  are  either  seashore  or  fluviatile  or  marsh 
deposits.  In  China  they  extend  over  the  northern  provinces,  Liau-tung, 
Chi'-li,  Shan-tung,  and  Shan-si,  and  there  is  probably  a  large  peninsula  in 
the  province  of  Hu-nan.  Beyond  China  they  are  of  general  occurrence 
in  the  ranges  of  Mongolia  and  Tibet,  which  rise  through  the  great  mantle 
of  desert  deposits. 

The  other  series  is  in  fact  a  great  single  formation,  a  limestone  which 
in  some  places  is  more  than  4,000  feet,  1,200  meters,  thick  and  is  charac- 
terized by  marine  fossils  throughout.  It  has  been  identified  south  of  the 
Ts'in-ling-shan  in  the  provinces  of  Shen-si,  Ssi'-ch'uan,  and  Hu-pe'i,  and 
further  east  along  the  Yang-tzi'-kiang  in  An-hui  and  Kiang-si.  It  occurs 
in  the  Kuen-lung  and  Nan-shan  mountains  of  Tibet,  and  also  in  the  Tien- 
shan  in  Turkestan.  It  is  furthermore  a  wide-spread  formation  throughout 
all  of  southwestern  China,  Burmah,  and  the  Malay  peninsula.  The  marine 
deposits  are  also  extensively  represented  in  the  Himalayas. 

I  first  take  up  the  account  of  the  marine  formations,  which  conform- 
ably succeed  the  Devonian,  and  next  the  interbedded  continental  and 
marine  formations  which  rest  unconformably  upon  older  rocks. 

MARINE   CARBONIFEROUS. 

The  first  description  of  the  Carboniferous  limestone  of  southern  China 
was  furnished  by  von  Richthofen,  who  gave  it  the  name  of  the  Ki-tau 
limestone,  from  a  locality  on  the  Yang-tzi'-kiang.  His  description  has 
been  given  in  connection  with  his  account  of  the  Devonian  of  the  same 
region. 

Three  hundred  and  seventy  miles,  600  kilometers,  west  of  von  Richt- 
hofen's  locality,  in  the  gorges  of  the  Yang-tzi'-kiang,  between  I-chang  and 

71 


72  RESEARCH    IN   CHINA. 

Wu-shan-hien,  the  Carboniferous  limestone  is  beautifully  exposed.  Its 
distribution  is  shown  on  the  geological  map  of  the  Yang-tzi  gorges,  plate 
xxxvi  of  volume  i  of  this  report.  It  was  also  repeatedly  crossed  in  the 
sections  on  the  Ta-ning-ho  in  eastern  Ssi'-ch'uan,  and  its  relation  to  the 
underlying  'strata  was  thus  repeatedly  observed  by  the  members  of  the 
expedition  of  1903-04.  The  greenish,  sandy,  and  bituminous  shales  of  the 
middle  Paleozoic  are  followed  by  calcareous  shales,  and  these  by  massive 
gray  limestones  in  which  layers  and  nodules  of  black  flint  constitute  a 
conspicuous  feature.  A  pink  limestone  at  the  top  of  middle  Paleozoic 
strata  yielded  a  few  fossils  already  referred  to  and  described  in  volumes 
I  and  HI  of  this  report.  They  are  not  earlier  than  Silurian  (Gothlandian) , 
may  probably  be  Devonian,  and  may  even  be  as  late  as  the  lower  Carbon- 
iferous (Mississippian) .  This  fauna  has  nothing  in  common  with  that  from 
the  base  of  the  gray  limestones  which  closely  overlie  it,  and  it  is  evident 
that  the  life  conditions  underwent  a  notable  change  between  the  two  epochs. 
Nevertheless  there  is  such  a  uniformity  of  sequence  in  repeated  sections 
that  the  strata  can  not  be  otherwise  described  than  as  conformable.  We 
are  thus  led  to  conclude  that  in  this  district  the  sequence  of  deposits 
which  began  with  the  lower  Cambrian  (Sinian)  limestone,  and  continued 
conformably  through  the  middle  Paleozoic,  remained  unbroken  through  the 
lower,  middle,  and  upper  Carboniferous.  Yet  it  is  to  be  noted  that  the 
sedimentation  from  late  Ordovician  to  upper  Carboniferous  time  was  very 
meager  and  may  possibly  have  ceased  altogether  at  intervals  in  the  middle 
Paleozoic. 

This  upper  Carboniferous  limestone,  which  we  distinguished  by  the 
name  Wu-shan  from  its  prominent  section  in  the  Wu-shan  gorge  of  the 
Yang-tzi,  is  probably  the  same  as  the  Ki-tau  limestone  of  von  Richthofen. 
But  until  the  faunas  have  been  more  fully  collected  and  the  geology  of  the 
entire  region  more  accurately  mapped,  it  is  as  well  that  they  should  be 
designated  by  separate  names. 

The  Wu-shan  limestone  exhibits  a  sequence  which  has  been  described 
by  Blackwelder  in  volume  i,  p.  275. 

In  the  district  in  central  China  which  has  just  been  described  we  have, 
so  far  as  the  faunal  evidence  goes,  a  large  development  of  the  upper  Car- 
boniferous and  only  a  very  meager  representation,  if  any,  of  lower  Carbon- 
iferous strata.  But  from  this  locality  toward  the  northwest  and  southwest 
Carboniferous  limestones  may  be  traced  through  the  observations  of  von 
Richthofen,  L6czy,  Obrutchov,  and  others,  and  they  are  apparently  not 
restricted  to  the  upper  Carboniferous.  De  Lapparent  gives  a  good  synop- 
sis* of  the  occurrence  of  the  older  Carboniferous  strata.  In  view  of  the 


*  Trait£  de  Geologic,  fifth  edition,  1906,  p.  914. 


CARBONIFEROUS   IN  GENERAL.  73 

very  meager  collections  which  have  been  obtained  it  is,  however,  hardly 
worth  while  to  attempt  to  distinguish  the  different  horizons  of  the  great 
limestone  formation  in  the  light  of  present  knowledge.  And  therefore,  in 
describing  its  distribution  I  shall  refer  simply  to  the  Carboniferous,  which 
may  include  both  lower  and  upper  or  either  one  of  them. 

Northwestward  from  the  Yang-tzi  gorges  Carboniferous  limestone  is 
known  to  form  conspicuous  ranges  in  northeastern  Ssi-ch'uan  and  southern 
Shen-si,*  and  through  the  work  of  Obrutchovf  and  LoczyJ  it  has  been  traced 
into  northeastern  Tibet,  where  it  is  more  particularly  represented  in  the 
southern  mountain  chains  of  the  Nan-shan.  In  the  section  observed  by 
L,6czy  near  Paj-suj-kiang  the  transition  from  fossiliferous  Devonian  strata 
to  the  gray  Carboniferous  limestone  is  accurately  described  as  one  of  strict 
conformity,  and  this  is  also  true  of  the  sections  given  by  von  Richthofen 
in  the  same  district  of  northern  Ss'i-ch'uan.  The  formation  in  this  district 
might  readily  be  confused  with  a  similar  limestone  of  Permian  age,  which 
rests  unconformably  on  the  folded  Paleozoics. 

The  expedition  of  1903-04  found  the  Carboniferous  limestone  and  argil, 
lite  constituting  a  recognizable  terrane  in  the  valley  of  the  Han  above  Hing- 
an-fu  and  in  the  Ts'in-ling-shan,  in  longitude  108°  east.  The  characteristic 
rocks  are  highly  carbonaceous;  they  vary  from  limestone  and  quartzite 
to  black  slate.  Their  Carboniferous  age  is  not  determined  by  fossils,  as 
they  are  more  or  less  metamorphosed,  but  it  is  inferred  with  confidence  on 
the  basis  of  their  commonly  carbonaceous  character  and  their  stratigraphic 
relations.! 

The  relations  of  the  Carboniferous  limestone  to  older  rocks  in  northern 
Tibet  are  not  clearly  expressed  in  the  available  literature.  Such  a  section 
as  that  of  Obrutchov's  of  the  Richthofen  range||  is  indefinite.  The  Car- 
boniferous is  represented  as  lying  between  folded  masses  of  rocks  that  are 
questionably  assigned  to  the  Silurian,  it  resting  unconformably  upon  the 
one  mass  and  being  overthrust  by  another.  The  structure  itself  is  unusual, 
as  it  is  delineated,  and  the  age  of  the  Silurian  rocks  being  doubtful  it  is 
not  possible  to  say  what  the  unconformity  means.  If  the  older  strata  are 
those  of  the  Nan-shan  sandstone  and  belong  to  the  latest  pre-Cambrian 
(Hu-t'o)  system,  as  has  been  suggested  in  the  chapter  on  that  subject, 
the  Carboniferous  in  this  northern  range  overlaps  upon  pre-Paleozoic 

*  China,  vol.  n,  p.  599. 

t Central  Asia  and  the  Nan-shan  Mountains,  Obrutchov,  vol.  n,  p.  356,  pi.  n  (in  Russian).  Also,  La 
Face  de  la  Terre,  K.  Suess,  vol.  in,  p.  271. 

J  Reise  des  Grafen  Sz£chenyi,  vol.  I,  p.  433. 

§See  chapter  on  the  Han  province,  vol.  i,  p.  300. 

II  Central  Asia  and  the  Nan-shan  Mountains,  vol.  n,  p.  164,  fig.  130.  Also  La  Face  de  la  Terre,  Suess, 
vol.  in,  p.  232. 


76  RESEARCH   IN   CHINA. 

(cb)  Dark  coal-bearing  shale,  with  slickens  covered  with  calcite.     The  thickness  of 
this  bed  could  not  be  estimated  closely  on  account  of  loose  stuff  on  the  slope,  but  I  could 
see  by  the  position  of  the  tunnels  that  below  this  shale  occurred 

(cc)  the  principal  coal-bed.     From  the  height  of  the  slope  the  thickness  of  cb  and  cc 
may  be  estimated  at  1 8  to  20  meters. 

(d)  Dark  or  black  bituminous  clay  marls,  with  fine  calcite  veins  and  full  of  fossils ; 
including  also  yellowish-gray  layers  of  mussel  shells.     I  saw  these  only  on  the  dumps ;  the 
thickness  is  therefore  unknown,  and  I  can  only  infer  that  they  occur  below  the  coal-bed. 

(e)  Gray,  bituminous,  marly  limestone,  which  occurs  on  the  southern  slope  from  the 
mines  and  in  the  foot  of  the  principal  mine;  which  alternates  with  thin  layers  of  coal,  and 
which  is  full  of  fossils. 

(/)  Yellow  sandstone,  colored  with  iron  hydroxide  and  in  part  shaly. 

The  thickness  of  the  strata  included  from  d  to  /  is  uncertain,  as  the  base  of  /  was  not 
visible;  but  all  the  strata  seen  on  the  southern  side  of  the  basin  lie  unconformably  on  the 
Nan-shan  sandstone,  which  dips  steeply  toward  the  south. 

L6czy  gives  a  list  of  fossils  which  serve  to  correlate  the  strata  with  the 
Russian  Upper  Carboniferous  (Mjatschkowo). 

There  are  many  references  in  the  works  of  Obrutchov  to  coal-bearing 
strata  in  Mongolia  and  the  Nan-shan.  In  some  cases  they  are  identified 
as  Carboniferous,  and  in  others  as  supra-Carboniferous.  The  conditions 
which  prevailed  in  Shan-si  were  general  throughout  central  Asia  north 
of  the  Tibetan  arm  of  the  Tethys,  and  the  deposition  of  continental  deposits 
containing  coal,  yet  interbedded  with  occasional  marine  limestones,  was 
wide-spread.  The  area  thus  characterized  reached  into  Turkestan  on  the 
west,  perhaps,  as  far  as  longitude  80°  east,  but  was  bounded  by  a  sea  on  the 
northwest,  where  the  Carboniferous  limestone  of  the  Ti6n-shan  mountain 
system  was  being  deposited. 


RESEARCH  IN   CHINA 


A.VKI  during  the  CarbanjfA 


PLATE  6 


LEGEND 


QUATERNARY 

AND 
TERTIARY 


CARBONIFEROUS    MARINE 
STRATA,  NOTGENERALLY 

COAL-BEARING 

'.l/rv/.VMv1///./'//  H'/iiclt  Ihrv 

are  Aywir//  ttnn-i-nf  i 


CARBONIFEROUS  COAL-BEARING 

STRATA, WITH  THIN    MARINE 

LIMESTONE  INTERBEDDED 


CARBONIFEROUS  LANDS 

agp 

to  r 


/'mill/ 


CHAPTER  VI.— PERMO-MESOZOIC 


TRANSITION  FROM  PALEOZOIC  TO  MESOZOIC! 

Theoretical  considerations. — There  is  no  sharp  plane  of  division  to  be 
discovered  between  the  Paleozoic  and  Mesozoic  in  Asia.  In  some  dis- 
tricts there  was  transition  of  sediment  and  of  faunas;  elsewhere,  during 
equivalent  time,  there  is  disturbance  of  physical  or  biological  conditions. 
In  one  place  a  decided  change  of  sediment,  in  another  an  equally  abrupt 
change  of  fauna,  in  a  third  an  unconformity  of  dip  between  beds  that 
differ  in  kind  and  in  fossils :  these  may  be  taken  as  local  dividing  planes ; 
but  they  do  not  range  themselves  into  one  horizon.  They  fall  anywhere 
within  the  later  Carboniferous,  or  within  the  Permian,  or  Trias.  It  is 
in  the  nature  of  things  that  a  great  transformation  of  features,  climates, 
and  faunas,  such  as  characterized  the  passage  from  the  period  of  the  Old 
Life  to  that  of  the  Middle  Life,  should  take  time,  and  that  the  evidences 
of  change  should  appear  at  different  geologic  moments  in  different  places. 
The  better  to  understand  the  facts  which  are  presently  to  be  listed,  we 
may  review  briefly  the  theoretical  sequence  of  events. 

The  leading  fact  that  distinguishes  the  early  Mesozoic  from  the  late 
Paleozoic  is  the  contrast  in  the  extent  of  the  lands,  which,  through  with- 
drawal of  the  epicontinental  seas,  became  relatively  very  wide.  This  change 
theoretically  resulted  from  enlargement  of  the  ocean  basins  by  subsidence 
and  widening,  which  was  associated  with  protuberance  of  the  continents 
and  local  deformation  of  rocks  by  folding.* 

There  is  no  question  about  the  leading  fact,  of  which  Asia,  as  well  as 
North  America,  offers  a  striking  illustration.  The  wide  seas  of  the  late 
Carboniferous  shrank,  in  the  Permian  and  Triassic,  to  embayments  around 
continental  platforms.  One  effect  of  that  shrinking  was  interference  of 
emerging  lands  with  circulation  of  marine  currents.  Hence  followed 
climatic  differentiation  and  contrasts  of  warm  and  cold  currents  in  the  seas 
and  sharper  contrasts  of  climatic  zones  on  lands.  A  further  effect  of  these 
changes  was  the  development  of  new  species  and  extinction  of  organisms 
incident  to  altered  conditions  of  habitat.  Faunal  change  was  evidently  a 
late  effect,  since  it  was  sequential  upon  the  others.  Do  these  phenomena 
afford  any  precise  datum  that  might  serve  to  distinguish  a  definite  epoch, 

*  Geology,  Chamberlin  and  Salisbury,  vol.  n,  p.  656. 

77 


78  RESEARCH   IN   CHINA. 

as  the  last  of  the  Paleozoic  or  the  first  of  the  Mesozoic,  an  epoch  that  could 
be  fixed  upon  as  contemporaneous  throughout  several  continents,  or  even 
within  one  extensive  continent?  It  does  not  appear  that  they  do. 

Granting  that  deepening  of  sea  basins  would  withdraw  the  continental 
seas  simultaneously  if  the  continents  stood  fast,  it  is  evident  that  the  lands 
would  emerge  soon  in  one  area  and  only  much  later  in  another  if  the  conti- 
nents were  here  rising  and  there  sinking,  as  was  the  case.  The  effects  of 
emergence,  i.  e.,  erosion  or  continental  aggradation,  were  therefore  not  even 
approximately  contemporaneous,  for  we  must  bear  in  mind  that  earth 
movements  are  slow.  Denudation  and  aggradation  were  among  the  earliest 
processes  to  become  active  and  the  longest  to  continue.  Among  the  Asiatic 
effects  are:  that  eroded  surface  which  uncovers  strata  ranging  from  the 
Carboniferous  down  to  the  Silurian  in  the  western  Himalayas;*  or  those 
extensive  continental  deposits  of  red  cross-bedded  sandstones  and  associated 
shales,  which  in  North  China  conformably  overlie  the  Upper  Carboniferous 
coal-measures. 

The  differentiation  of  local  climates  from  the  preexisting  conditions 
of  a  general,  somewhat  uniform  climate  may  reasonably  be  compared  with 
similar  changes  during  the  Pliocene  and  Pleistocene,  following  upon  the  gen- 
eral mildness  of  the  Tertiary.  The  Paleozoic-Mesozoic  transition  presents 
even  more  remarkable  extremes,  such  as  the  wide  occurrence  and  persistence 
of  the  Gondwana  flora  and  the  development  of  centers  of  glaciation  in 
India  and  Australia.!  Regarded  as  an  effect  of  refrigeration  and  aridity, 
the  formation  of  iron  oxide  in  quantity  can  not  have  been  an  immediate 
result;  geographic  and  meteorologic  changes  had  progressed  notably  before 
the  deposition  of  red  rocks  could  have  become  general. 

Marine  organisms,  evolving  in  ocean  waters  (that  in  contrast  to  air 
constitute  a  medium  which  is  extremely  conservative  in  maintaining  the 
conditions  of  life)  are  long  protected  against  change  and  also  very  sensitive 
to  change,  especially  of  temperature.  Thus  it  is  not  surprising  that  in 
some  ocean  currents  where  the  mildness  of  Carboniferous  seas  was  main- 
tained, Paleozoic  forms  should  have  lived  on,  even  after  their  habitat  had 
been  invaded  by  Mesozoic  types,  as  witness  the  Productus  limestone  of 
India;  or  that  elsewhere,  on  the  diversion  of  warm  waters  and  occupation 
of  their  territory  by  chillier  ones,  there  should  be  speedy  extinction,  even 
of  a  whole  fauna.  Even  though  the  endurance  of  the  adult  be  consider- 
able, that  of  the  larva  is  very  slight,  and  the  latter  is  the  critical  factor. 
When  we  thus  consider  the  physical  conditions  which  permit  or  limit  the 
existence  of  species,  the  value  of  fossils  as  evidence  of  contemporaneity  is 

*Haydcn:  Memoirs  Geological  Survey  of  India,  xxxvi,  pt.  I,  p.  52. 

t  Textbook  of  Geology,  A.  Geikie,  vol.  11,  pp.  1058,  1079,  and  numerous  references  there  given. 


CORRELATION  AND  UNCONFORMITY.  79 

qualified  by  the  geographic  phase  during  which  the  organisms  lived.  In 
the  world-wide  Carboniferous  seas  marine  organisms  attained  cosmopolitan 
distribution;  and  correlation  between  Europe,  Asia,  and  America  rests 
upon  a  firm  paleontologic  basis;  but  when  those  seas,  so  far  as  their  epi- 
continental  parts  were  concerned,  became  transformed  into  bays,  straits, 
carribbeans,  and  mediterraneans,  organisms  met  with  great  variety  of  expe- 
rience. Where  favored  they  persisted  or  slowly  evolved;  where  adversely 
conditioned  they  died  out  or  varied,  and  cosmopolitan  relationships  gave 
place  to  provincial  diversity.  That  they  did  so  sooner  here  and  later 
there,  and  that  the  old  sometimes  returned  to  a  habitat  from  which  it 
had  been  driven  during  a  temporary  unfavorable  condition,  is  the  record  of 
stratigraphy  and  paleontology.*  It  follows  that  correlations  on  a  paleon- 
tologic basis  are  less  reliable  during  the  transition  from  Paleozoic  to  Meso- 
zoic  than  during  those  periods  of  more  general  conditions  which  preceded 
and  followed;  and  that  even  though  Permian  and  Triassic  faunas  were 
more  abundant  and  better  known  than  they  are  in  Asia,  we  should  still 
have  difficulty  in  establishing  a  plane  with  reference  to  which,  in  central 
Asia,  China,  Australia,  and  India,  we  could  say:  that  which  is  beneath  is 
Paleozoic  and  that  which  is  above  is  Mesozoic.  There  is  no  such  general 
plane. 

Unconformity  is  a  condition  common  to  a  transition  stage,  regarding 
which  a  word  is  necessary  in  explanation  of  the  diversities  which  Chinese 
sections  present.  The  term  covers  a  great  range  of  phenomena  indicating 
discontinuity  of  deposition,  from  that  which  may  result  from  nondeposi- 
tion,  marine  scour,  or  subaerial  erosion,  without  obvious  disturbance,  to  the 
most  striking  differences  of  structure.  We  are  apt  to  think  of  a  submerged 
surface  as  one  subject  to  sedimentation,  or  vice  versa  of  a  surface  which 4 
has  not  received  sediment  as  one  which  must  have  been  above  water;  but 
the  inference  is  not  valid  in  view  of  the  fact  that  marine  currents,  when 
confined  in  straits  or  shallows  to  such  an  extent  that  the  water  next  the 
bottom  moves,  are  capable  of  carrying  sediment  past  a  district,  or  even  of 
scouring  the  bottom.  Considering  the  work  of  corrasion  done  by  rivers 
whose  depth  and  bottom  pressure  are  relatively  insignificant,  the  capacity 
of  marine  currents  to  scour  can  not  be  questioned,  provided  the  waters  are 
equipped  with  abrading  materials  in  the  form  of  silt,  fine  sand,  or  siliceous 
spicules.f  Nondeposition  during  an  indefinite  time  or  corrasion  of  an 
undisturbed  stratum  may  result.  It  is  thus  that  we  may  explain  the 
contrast  of  strata  where  the  Carboniferous  limestone  is  concordantly  over- 
lain by  red  terrigenous  deposits,  as  in  eastern  Ssi'-ch'uan.  The  limestone 

*  Williams:  Devonian  Section  of  Ithaca,  New  York,  Journal  of  Geology,  vol.  xv,  p.  m,  October,  1906. 
t  Agassiz:  Three  Cruises  of  the  Blake,  vol.  i,  pp.  136-139. 


80  RESEARCH   IN   CHINA. 

which,  after  the  manner  of  lime  deposits,  presumably  hardened  in  course 
of  accumulating,  may  be  supposed  to  have  been  swept  clean  in  a  shallow- 
ing gulf  or  strait  until  the  current  was  checked  and  the  terrigenous  sedi- 
ments from  nearby  land  were  laid  down.  It  is  evident  that  the  strata 
in  contact  with  the  limestone  may  be  nearly  continuous  with  it  or  indefi- 
nitely younger  than  it. 

On  the  other  hand,  apparently  at  the  other  extreme  of  unconformity, 
we  have  strata  extended  across  eroded  folds,  with  marked  discordance  of 
dip.  In  a  case  described  by  von  Richthofen  and  Loczy  near  Kuan-yuan- 
hien  in  northeastern  Ssi'-ch'uan,  erosion  has  laid  bare  Silurian  strata  on  an 
anticline  including  several  thousand  feet  of  Paleozoics,  and  the  overlapping 
formation  is  possibly  Permian,  more  probably  Triassic  limestone.  There  is 
no  doubt  of  folding,  which  resulted  in  a  more  or  less  elevated  range,  accom- 
panied by  erosion  which  reduced  that  range  to  a  peneplain.  The  obscure 
feature  is  the  answer  to  the  question:  how  does  the  unconformity  consist 
with  the  fact  that  in  nearly  adjacent  regions  strata  are  concordant  in  dip, 
from  Carboniferous  to  Jurassic;  such  being  the  case  on  the  middle  Yang- 
tzi,  in  eastern  Ssi'-ch'uan,  200  miles,  320  kilometers,  distant.*  I  take  it  that 
the  phenomena  illustrate  two  things  which  are  by  no  means  peculiar  to 
Central  China.  The  first  is  that  effects  of  folding  are  localized  in  linear  belts 
and  may  be  very  decided  in  certain  zones  which  lie  adjacent  to  others  that 
do  not  share  in  the  disturbance;  which  remain,  for  instance,  the  bottoms 
of  deep  synclinoria.  And  the  other  is  that  the  growth  and  wasting  of  an 
elevation  due  to  folding  takes  no  longer  than  the  transition  period  from 
Paleozoic  to  Mesozoic.  How  long  that  was  it  is  difficult  to  say,  but  in  geo- 
logic terms  it  included  the  latest  Carboniferous,  the  Permian,  and  part  of 
Trias,  in  Asia;  and  probably  exceeded  Pliocene  and  Pleistocene  time, 
judging  by  the  effects  of  mountain  growth  and  planation. 

PERMO-TRIASSIC  STRATA. 

Angara  series. — There  are  in  Asia  two  series  of  continental  deposits 
which  are  approximately  contemporaneous,  but  are  geographically  distinct. 
They  both  include  members  which  range  in  age  from  Permian  to  Lower 
Jurassic,  and  thus  cover  the  Paleozoic-Mesozoic  transition  period.  The  one 
is  the  well-known  Gondwana  series  of  the  Indian  peninsula,  the  other  the 
Angara  series  of  Siberia  and  the  Altai  region. f  Representatives  of  the 
Gondwana  series  have  been  identified  in  Indo-China  and  also  in  Australia. 
These  districts  lie  south  of  the  great  central  mediterranean  of  Asia,  to  which 
Suess  has  given  the  name  of  Tethys,  whereas  the  occurrences  of  the  Angara 

*  Research  in  China,  vol.  i,  chapter  xui,  pp.  285  et  seq. 
f  La  Face  de  la  Terre,  Suess,  vol.  HI,  p.  37. 


PERMO-MESOZOIC.  8 1 

series  lie  north  of  that  sea,  on  the  continent  of  Angara.  It  is  probable 
that  the  continental  area  extended  from  the  Gobi  region  of  central  Asia, 
eastward  to  the  present  coast  line  or  beyond  it,  and  southward  beyond  the 
site  of  the  Ts'in-ling-shan,  south  of  which  it  was  bounded  by  the  Tethys. 
We  thus  place  in  the  Angara  series  the  terranes  which  are  about  to  be 
described. 

Strata  which  are  assigned  provisionally  to  horizons  ranging  from  Per- 
mian to  Rhaetic,  inclusive,  are  widely  distributed  in  China,  from  Shan-tung 
on  the  east  to  Mongolia  on  the  west  and  from  Shan-si  in  the  north  to  Indo- 
China  in  the  south.  The  identification  of  the  coal-bearing  series  as  Rhaetic 
rests  on  fossil  plants  and  is  usually  qualified  by  an  alternative  assignment 
to  Lower  Jurassic.  Without  attempting  to  prejudge  the  definite  correla- 
tion these  formations  are  discussed  in  this  section. 

In  central  Shan-tung  observations  by  the  expedition  of  1903-04  with 
reference  to  Permo-Triassic  strata  were  made  in  the  vicinity  of  Lai-wu-hien, 
and  are  described  in  volume  i,  in  the  chapter  on  stratigraphy  under  the 
Sin-t'an  District.  They  are  much  less  complete  than  is  desirable,  since  our 
attention  was  given  chiefly  to  the  older  rocks,  and  in  the  sections  which  we 
could  conveniently  observe  there  were  gaps  covered  by  alluvium  at  those 
points  where  we  should  expect  the  passage  from  known  Carboniferous  to 
supposed  Permian.  Carboniferous  beds,  identified  by  marine  fossils  in  a 
bituminous  limestone  interbedded  in  the  coal-bearing  sandstones  and  shales, 
were  followed  by  red  cross-bedded  sandstones.  On  account  of  their  color 
we  have  regarded  the  latter  as  Permian,  and  we  take  them  to  be  of  fluvia- 
tile  origin.  Succeeding  these,  but  in  interrupted  succession,  occur  red,  black, 
and  greenish  shales  interbedded  with  basaltic  flows.  There  is 
evidence  that  throughout  an  area  including  practically  all  the  central 
of  Shan-tung  there  was  a  volcanic  district  from  which  eruptions  w 
numerous  and  extensive.  The  activity  began  probably  during  the  latest 
Paleozoic  and  continued  well  into  the  Mesozoic.  In  volume  i  these  vol- 
canics  have  been  classed  with  the  Carboniferous,  that  systematic  term 
being  extended  to  cover  the  Permian. 

Overlying  the  volcanic  series  near  Yen-chuang,  Shan-tung,  occur  beds 
designated  by  us  as  the  Sin-t'ai  series,  and  by  von  Richthofen  and  Lorenz 
assigned  to  the  Jurassic.  In  the  Sin-t'ai  area  they  are  exposed  with  a 
thickness  of  several  thousand  feet,  as  gray  to  red  sandstones  and  shales 
with  thin  beds  of  conglomerate.  Von  Richthofen  included  with  them  the 
adjoining  coal-bearing  rocks  of  Ts'ai-kia-chuang  ("  Tsing-ko-tschwang ") , 
but  on  the  evidence  of  the  plants  collected  Schenck  placed  the  coal-measures 
of  that  locality  in  the  Carboniferous. 

In  the  coal  basin  of  Wei-hien  von  Richthofen  observed  the  occurrence 
of  coal-beds  in  close  proximity  to  granite,  an  exceptional  relation,  since 


82  RESEARCH   IN   CHINA. 

the  deposits  he  had  seen  previously  were  in  strata  conformable  to  his 
Kohlenkalk  (Sinian).  Those  were,  however,  of  Carboniferous  age,  whereas 
these  may  probably  be  of  Lower  Jurassic,  according  to  plants  collected  by 
Lorenz  and  described  by  Potonie. 

Throughout  northwestern  China,  from  the  eastern  outcrops  of  the  Car- 
boniferous coal-measures  west  of  Peking  and  the  western  margin  of  the  great 
plains,  the  area  of  red  and  yellow  sandstones  overlying  the  coal-measures  is 
very  extensive.  Von  Richthofen  called  these  strata  "  Ueberkohlensand- 
steine "  or  "  Plateauschichten, "  on  account  of  their  relation  to  the  coal- 
measures,  their  indeterminate  age,  and  their  occurrence  in  the  extensive 
synclinoria  which  form  the  elevated  districts  of  Shan-si.  He  gives  but 
one  section,*  in  which  he  distinguishes  from  below  upward  the  following 
members : 

(1)  Sandstone  and  shale  of  the  coal-measures  with  several  small  coal-beds. 

(2)  The  principal  anthracite  bed  which  is  accompanied  by  black  slates. 

(3)  A  series  of  mostly  dark  shales  and  soft  yellow  sandstones. 

(4)  Reddish  yellow  clayey  shales  with  occasional  thin  sandstone  layers. 

(5)  Green  and  red  shales,  which  are  very  thin-bedded  and  hard  and  break  up  into 
fine  debris.     These  are  interbedded  with  some  thin  sandstones  which  form  benches. 

(6)  Soft  and  also  hard  sandstones,  heavily  bedded ;  100  feet  thick. 

(7)  Bright-colored  shales  like  those  in  5,  which  also  alternate  with  a  few  sandstone 
beds.     The  principal  colors  are  green,  gray,  blue,  and  red ;  thickness,  1 20  feet. 

(8)  Firm  sandstones  of  a  greenish  color,  very  evenly  bedded  with  white  mica ;  in  part 
containing  quartz  grains  as  large  as  peas,  which  also  occur  of  still  larger  size  and  form 
solid  conglomerates. 

(9)  Shales  and  sandstones  of  dominantly  red  color. 

The  last  member  is  probably  not  the  top  of  the  series,  the  total  thick  - 
of  which  is  estimated  at  3,000  feet,  whereas  that  of  the  underlying 
-measures  (which  are  included  in  the  preceding  section)  is  said  to  vary 

from  400  to  600  feet.f 

At  Ta-tung-fu,  northern  Shan-si,  f  is  a  sequence  of  strata  which  is 

peculiar  not  only  in  being  remote  from  other  similar  basins,  but  in  the 

great  thickness  of  strata  and  of  the  individual  coal-beds.     Von  Richthofen 

describes  it  as  follows: 

Lower  Jura;  coarse  quartzose  sandstones  with  clayey  matrix,  interbedded  with  white 
strata  of  tripoli  and  also  of  siliceous  calcareous  formation,  both  containing  remains  of  plant 
stems;  also  coal-beds,  which  are  associated  with  black  shales.  The  visible  thickness  is 
1,200  feet.  The  character  and  color  of  the  strata  vary  continually.  The  strike  is  north 
30°  east,  the  dip  is  in  a  direction  north  60°  west,  at  first  at  an  angle  of  40°,  which  lessens 
to  10°,  and  the  upper  beds  lie  almost  flat. 


*China,  Tol.  n,  pp.  414-415. 

^Ibid.,  page  453. 

%Ibid.,  vol.  n,  pp.  356-359- 


LOWER   YANG-TZI.  83 

The  strata  below  the  Jurassic  are  Sinian,  and  the  relation  is  no  doubt 
one  of  unconformity  by  erosion,  but  the  stratification  is  approximately 
parallel  in  the  Sinian  and  Jurassic  beds,  and  the  contact  was  not  seen  in  the 
section  described  in  the  above  quotation.  In  an  adjoining  section,  however, 
near  "Hei'-ku-tsze,"*  the  unconformable  contact  of  the  two  series  was 
observed  and  is  represented  in  the  diagrammatic  section  as  one  of  uncon- 
formity of  dip  as  well  as  of  erosion. 

CENTRAL  CHINA. 

Under  this  head  I  consider  the  occurrence  of  Permo-Mesozoic  strata 
along  the  Yang-tzi,  in  the  Ts'in-ling-shan,  and  in  the  Red  Basin  of  Ssi-ch'uan. 

I  begin  the  enumeration  of  the  known  occurrences  with  that  which  is  at 
once  the  most  eastern  and  also  the  first  recorded,  the  deposits  in  the  valleys 
adjacent  to  the  Yang-tz'i,  between  Han-kow  and  Nan-king,  as  described  by 
von  Richthofen,  who  says:f 

Sanghu  sandstone  and  conglomerate. — The  deposition  of  the  Kitau  limestone  ended 
with  a  considerable  disturbance,  as  the  next  formation  follows  quite  unconformably.  It 
consists  of  a  quartzose  sandstone  and  quartzose  conglomerate,  interstratified  with  thick 
layers  of  red  clay,  and  carries  a  coal-bed  at  a  place  sixty  miles  below  Hankau.  Black 
shales,  which  overlie  the  coal,  carry  some  remains  of  plants.  I  was  unable  to  establish 
the  thickness  of  this  formation. 

Commencement  of  the  outbreaks  oj  porphyry. — The  porphyritic  eruptions  have  probably 
continued  in  China  during  a  long  period  while  sediments  were  contemporaneously  deposited. 
Pumpelly  was  the  first  to  direct  attention  to  these  wide-spread  events.  But  it  is  only  in  the 
great  granitic  region  of  the  eastern  coast,  between  Ning-po  and  Hong-kong,  that  porphyry 
itself  arrives  at  an  extraordinary  development.  The  Chusan  islands  are  almost  exclusively 
composed  of  quartzose  porphyry  and  its  tufas,  and  from  there  southward  it  appears  to  be 
only  subordinate  in  quantity  to  the  granite.  I  know  it  from  my  own  observations  on 
island  of  Hong-kong,  and  by  inference  from  the  observations  of  others  of  the  region  betwi 
that  island  and  Ning-po.  This  is  the  most  extensive  development  of  porphyry  known 
any  part  of  the  world. 

Deposits  of  porphyritic  tufa,  sandstones,  and  clays. — The  porphyries  themselves  are 
little  developed  on  the  lower  Yang-tze.  I  noticed  their  first  appearance  in  certain  porphy- 
ritic tufas  which  overlie  somewhat  unconformably  the  Sanghu  sandstone.  The  latter 
appears,  indeed,  from  its  purely  siliceous  character,  to  have  been  antecedent  to  any  out- 
break of  porphyry,  while  the  soft  and  impure  nature  of  all  subsequent  deposits  goes  to  show 
that  they  were  the  tufaceous  sediments  of  eruptions  in  remote  regions.  The  visible  thick- 
ness of  this  formation  below  Hankau  is  about  3,500  feet.  It  incloses  a  few  beds  of  coal 
of  subordinate  value. 

Herewith  ends  on  the  Yang-tze  the  series  of  ancient  formations. 

It  will  be  observed  that  von  Richthofen  gives  no  clue  to  the  age  of  these 
deposits,  which,  in  view  of  the  unconformity  at  their  base,  probably  do  not 
include  the  earlier  transition  sediments,  but  may  comprise  the  Triassic  and 

*  China,  vol.  n,  p.  368. 

t  American  Academy  Arts  and  Sciences,  vol.  vni,  1869,  p.  117. 


84  RESEARCH    IN   CHINA. 

also  the  Lower  Jurassic.  The  Sang-hu  is  thus  probably  nearly  equivalent 
to  the  Kui-chou  series. 

On  the  Yang-tzi  still,  but  several  hundred  miles  further  west,  occur  the 
exposures  of  Permo-Mesozoic  strata  which  form  the  foothills  along  the  moun- 
tains of  western  Hu-pei.  Pumpelly  described  them  as  he  saw  them  near 
I-chang,  and  his  account  is  given  in  volume  I,  p.  278,  of  this  report.  Vogel- 
sang* repeatedly  refers  to  them  as  being  observed  in  a  trip  from  I-chang 
northward  as  far  as  the  32d  parallel,  from  which  he  returned  via  Chu- 
shan  and  the  Ta-ning-ho;  the  latter  part  of  his  route  coincides  with  that 
subsequently  followed  by  our  expedition. 

We  observed  strata  above  the  Upper  Carboniferous  (Wu-shan)  lime- 
stone in  numerous  sections  on  the  Ta-ning-ho  and  Yang-tzi'-kiang,  but 
did  not  examine  them  closely.  There  was  great  uniformity  of  stratification 
and,  despite  the  marked  difference  between  the  massive  limestone  and  the 
red  shales  which  followed  it,  seemingly  perfect  conformity  of  dip  between 
the  two.  Both  in  the  field  and  since,  I  have  regarded  the  relations  as  those 
which  result  from  marine  scour  by  shallowing  waters.  The  limestone, 
having  accumulated  and  hardened  beneath  waters  which  were  deep  enough 
to  permit  sediments  to  gather,  was  swept  clean  by  a  current  which  flowed 
across  it,  possibly  with  accelerated  velocity,  while  the  waters  shallowed; 
and  ultimately,  in  consequence  of  continued  shallowing,  the  current  was 
checked  or  diverted  and  red  terrigenous  deposits  were  laid  down  on  the 
scoured  surface.  This  sequence  implies  the  nearness  of  land  areas  and 
possibly  of  subaerial  erosion  of  the  Wu-shan  limestone  in  adjacent  areas 
to  a  degree  consistent  with  the  occurrence  of  such  conglomerate  of  flints 
we  observed  in  the  float  of  the  Ta-ning-ho.  f 

In  the  limestone,  400  feet,  120  meters,  above  the  base  of  the  red  series, 
'cur  fossils  which  Girty  refers  to  the  late  Paleozoic,  but  with  doubt.  J  He 
says: 

The  evidence  upon  which  the  horizon  in  question  is  referred  to  the  Paleozoic  con- 
sists of  the  septiferous  Terebratuloid,  the  round  crinoid  stems,  and  the  general  Paleozoic 
complexion  of  the  meager  fauna.  It  is  inconclusive  and  may  not  stand  against  any  facts 
which  strongly  point  to  a  Mesozoic  age.  For  this  reason  my  assignment  to  the  Carbonif- 
erous is  provisional  merely,  and  should  the  necessity  arise  of  changing  to  a  younger  period, 
the  readjustment  would  entail  no  serious  conflict  of  evidence. 

Girty 's  conclusion  from  the  fossils  is  in  accord  with  the  stratigraphic 
evidence  that  deposition  was  more  nearly  continuous  here  than  in  areas 
adjacent  on  the  north  and  west.  The  episode  of  marine  scour,  which  is 

*Reisen  in  nordlichen  und  mittleren  China,  Petermanns  Mitt.,  1901,  47,  and  1904,  50. 

fVol.  i,  pp.  264  and  277. 

t  Report  on  Upper  Paleozoic  Fossils,  vol.  m. 


MARGIN  OP  THE   RED   BASIN.  85 

supposed  to  account  for  the  sharp  contact  of  the  red  shale  on  the  Wu-shan 
limestone,  may  be  assumed  to  be  of  less  duration  than  that  represented  by 
marked  unconformity  of  dip;  and  therefore  the  strata  succeeding  upon  the 
area  of  marine  scour  would  probably  be  older  than  those  transgressing  upon 
the  area  of  subaerial  erosion.  The  former  might  be  late  Paleozoic,  as  Girty 
suggests.  The  latter  probably  range  from  early  Mesozoic  to  Jurassic. 

The  middle  Yang-tz'i  region,  where  the  strata  have  been  observed  by 
Pumpelly,  von  Richthofen,  and  ourselves,  is  continuous  on  the  west  with  the 
Red  Basin  of  Ssi'-ch'uan.  The  next  notable  observations  on  the  Paleozoic- 
Mesozoic  rocks  relate  to  the  northern  margin  of  that  basin  near  Kuan-yiian- 
hien,  in  the  region  reached  by  von  Richthofen,  Loczy,  and  Obrutchov,  and 
already  several  times  referred  to. 

South  of  the  section  exposed  by  the  Kia-ling-kiang  across  the  folded 
Paleozoics  are  strata  which  dip  gently  southward  into  the  Red  Basin.  There 
is  a  marked  unconformity,  above  which  the  first  formation  is  a  massive 
limestone.  Von  Richthofen  regarded  it  as  probably  Permian  or  Triassic.* 
Loczy  describes  the  section  observed  by  von  Richthofen  in  nearly  the  same 
terms, t  and  refers  the  limestone,  which  has  a  thickness  of  1,400  feet,  400 
meters,  or  more,  likewise  to  Permian  or  Triassic.  He,  however,  leaves  the 
possibility  of  a  still  younger  age  (Rhaetic)  open.  In  certain  thin-bedded, 
light-colored,  marly  limestones,  which  are  the  uppermost  strata  of  the  folded 
series  beneath  the  undisturbed  supposed  Permian  limestone,  he  collected 
indistinct  fossils,  on  which  he  comments  as  follows  :J 

Among  the  materials  which  I  collected  there  occur  a  cast  which  resembles  Megalo- 
donta,  an  Aviculopecten,  as  well  as  numerous  examples  of  that  little  bivalve  which  we  com- 
monly designate  by  the  indefinite  name  of  Myacites.  These  forms  permit  us  to  suppose 
that  the  marly  clays  and  thin-bedded  limestones  which  overlie  the  supposed  Carboniferous*., 
sandstone  may  be  of  Upper  Carboniferous  age,  and  that  they  perhaps  are  the  southern 
representatives  of  the  North  China  supra-Carboniferous  series.  But  the  possibility  is  not  "* 
excluded  that  even  Permian  and  Triassic  may  be  included  among  these  disturbed  strata, 
and  that  the  evenly  bedded  limestone  which  occurs  at  the  base  of  the  middle  Jurassic  sand- 
stones, in  the  Basin  of  Ssi'-ch'uan,  may  belong  to  the  Rhsetic  system.  I  found,  in  fact, 
the  traces  of  this  system  in  the  western  margin  of  the  Basin  of  Ssi'-ch'uan,  as  we  shall  see 
further  on. 

The  observation  to  which  Loczy  refers  in  the  preceding  paragraph  is 
probably  that  which  he  records  on  pages  736  to  739.  In  an  excursion  in 
the  vicinity  of  Tschung-tjen  he  observed  Triassic  strata  which  were  appar- 
ently conformably  bedded  between  two  heavy  limestones,  both  of  which  he 
assigns  to  the  Carboniferous.  He  explains  the  relations  by  a  conformable 

*  China,  vol.  n,  p.  603.     Quoted  in  full  in  this  report,  vol.  I,  p.  295. 
t  Reise  des  Grafen  Sze'chenyi,  vol.  I,  pp.  439-440. 
\Ibid.,  vol.  I,  p.  441. 


86  RESEARCH   IX  CHINA. 


itact  at  the  base  and  an  overthrust  above.  The  Triassic  strata  consist  of 
sandstones  and  fine-grained  sandy  shales,  which  contain  several  species  of 
Myophoria,  as  well  as  impressions  of  Encrinms  liliiformis,  together  with 
other  well-preserved  forms.  The  locality  is  in  western  Yun-nan,  latitude 
28°,  longitude  100°  east. 

The  Red  Basin  of  Ssa-ch'uan  was  first  explored  by  von  Richthofen.  but 
his  observations  still  remain  unpublished.  Loczy  crossed  the  northwestern 
margin  only,  yet  his  account  affords  the  best  available  information.*  It  is 
quoted  in  the  section  on  the  Jurassic. 

The  occurrences  which  have  been  described  for  the  Yang-tzl  and  Ssl- 
ch'nan  are  those  of  strata  south  of  the  metamorphic  district  of  the  Han 
valley,  which  borders  the  southern  Ts'in-Kng-shan.  In  the  vicinity  of  Shl- 
ts'uan-hien,  along  the  middle  course  of  the  Han,  and  in  that  part  of  south- 
eastern Shen-si  which  hes  between  Hing-an-fu  and  Chon-p'ing-hien.  the 
expedition  of  1903-04  observed  certain  schists,  which  appear  to  hold  the 
stratigraptnc  position  of  the  Kui-chou  series  and  to  have  the  mineralogical 
character  that  metamorphic  rocks  derived  from  those  sediments  should 
have.  They  have  been  described  in  volume  i,  chapter  xrv. 

We  observed  these  metamorphosed  Permo-Mesozoic  strata  about  Shi- 
ts'uan-hien  in  latitude  33°,  longitude  108°  30*  east.  The  next  occurrence 
toward  the  west  which  may  be  a«JgiiMl  to  this  horizon  is  described  by 
Loczy ,"f  and  presents  peculiar  characters.  It  Bes  north  of  Kuan-vuan-hien 
and  is  involved  in  the  folds  of  the  Pakozoks  near  Chau-tien.  The  strata 
overtie  the  typical  Carboniferous  limestone  and  consist  of  slaty  limestones 

sheared  day  slates,  which  are  reddish-brown  in  color  and  inclose  large 
blocks.  Loczy  suggests  that  they  are  of  Silurian  age  and  are 
•  overthrust  on  the  Carboniferous,  and  this  may  be  the  case.  But  it  seems 
«quaUy  probable  that  the  beds  are  Permo-Mesozoic  and  differ  from  those  of 
the  same  age  near  Kuan-yuan-hien  simply  in  degree  of  slatiness.  If  so,  the 
relations  are  similar  to  those  which  exist  between  the  altered  rocks  north 
of  Cbon-p'mg-hien,  Shen-si,  and  the  unaltered  beds  south  of  that  town. 
The  fnchiaioB  of  large  Kmestooe  blocks  is  not  explained.  They  may  be 

ites,  or  of  autoclastic  nature. 

JURA 


Jurassic  strata  occur  extensively  in  central  and  southern  China,  and 
also  in  northeastern  China  in  the  provinces  of  Shan-tung  and  Liau-tung. 
The  basin  of  Jurassic  coal-bearing  strata  near  Ta-tung-fu  in  northern  Shan- 
si,  longitude  113°  ffyfrt  latitude  40°,  J  is  apparently  an  isolated  occurrence 


I,  PL  6*5. 


OCCURRENCES   OF   JURASSIC.  87 

far  to  the  northwest,  beyond  which  in  Mongolia  no  deposits  of  similar  age 
occur.*  Following  the  trend  of  the  mountain  ranges  from  Ta-tung-fu 
southwest  through  Shan-si,  we  come  upon  the  Jurassic  in  the  eastern  Ts'in- 
ling-shanf  whence  it  may  be  traced  through  various  synclines  westward 
across  Shen-si  to  the  Red  Basin  of  Ssi-ch'uan.  The  line  thus  followed 
constitutes  the  northern  limit  beyond  which  neither  Loczy  nor  Obrutchov 
report  any  observations  of  Jurassic  deposits. 

The  formations  of  this  period  in  China  are  of  the  continental  type. 
They  consist  chiefly  of  sandstones,  with  shale,  generally  red,  more  or  less 
associated  with  coal,  devoid  of  marine  fossils,  but  characterized  by  plants 
which,  north  of  Indo-China,  do  not  contain  Gondwana  species,  but  are 
frequently  related  to  Russian  Jurassic  forms. 

I  proceed  to  the  enumeration  of  some  characteristic  occurrences. 

In  Shan-tung,  in  the  coal-basin  of  Wei-hien,  are  strata  from  which 
Lorenz  collected  Jurassic  plants.* 

In  the  eastern  Ts'in-ling-shan,  near  Shan-chou  in  Shen-si,  Loczy 
observed  a  basin  of  Jurassic  strata  which  rest  on  ancient  metamorphic 
schists.  He  says:  5 

Back  of  Shan-chou  the  valley  is  bounded  by  steep  cliffs,  in  which  the  steeply  up- 
turned transgression  of  the  basin  deposits  is  dearly  exposed.  As  is  shown  in  fig.  30  a, 
the  conglomerate  beds  which,  in  a  gently  mrKnfd  attitude,  underlie  Shan-chou,  assume 
a  constantly  steeper,  almost  vertical  dip  ;  they  are  underlain  by  fine-grained  dayey  sand- 
stones alternating  with  dark  marrv  fevers,  and  nnaflv  there  come  in  dark,  bituminous, 
thin-bedded  marls,  with  thin  sandstone  layers.  These  last  constitute  the  lowest  strata 
in  the  basin,  and  are  much  folded  as  a  whole  in  a  width  of  a  kilometer.  In  the  marl  as 
well  as  in  the  sandstones  occur  numerous  carbonized  fruits  (carpoh'thns)  which 


described  as  belonging  to  cycads  or  as  coniferous  fruits  resembling  tnrimm     According  to 
him  they  resemble  the  fruits  of  Bairia  or  Gingko  of  the  Jurassic  of  Siberia. 

The  occurrence  thus  described  by  Loczy  is  peculiar,  in  that  it  Kes  so 
far  in  the  heart  of  the  Ts'in-ling-shan  and  the  strata  are  more  strikingly 
folded  than  is  common  with  those  of  like  age. 

Some  miles  south  of  the  above-described  occurrence,  between  "Tse- 
chuen"  and  ''Kiu-tze-kuan,"  Loczy  crossed  an  extensive  basin  filled  with 
deposits  which  lie  in  horizontal  attitude  and  consist  of  the  local  sediments 
from  the  surrounding  mountains.  He  speaks  of  them  as  Mesozoic,  but 
does  not  cite  any  evidence,  and  it  would  appear  not  improbable  that  they 
are  of  later  age. 

*L£czy:  Rose  des  Gnfca  Si&Jumji,  rot.  n.  p.  799. 

trtii,  voL  n,  p.  415. 

t  Beitrage  mr  Geologic  Skan-toag*,  Heft  L 

§Reae  des  Gnfen  Szeckeoji,  TOt  i,  p.  415.  if.  yt  *. 


88  RESEARCH   IN   CHINA. 

Strata  which  we  provisionally  assign  to  the  Jurassic  occur  at  Sh'i- 
ts'iian-hien  on  the  Han  river,  in  the  form  of  red  and  yellow  sandstone  and 
conglomerate  composed  of  the  detritus  from  older  rocks  of  the  vicinity. 
The  area  is  apparently  limited  and  owes  its  present  position  and  preser- 
vation from  erosion  to  a  fault  by  which  the  soft  young  strata  are  brought 
to  a  relatively  low  level  among  the  metamorphosed  Paleozoics.* 

Still  farther  west,  in  the  northern  margin  of  the  Red  Basin,  are  the 
Jurassic  beds  near  Kuan-yuan-hien,  which  were  first  recognized  by  von 
Richthofenf,  again  observed  by  I^oczy.J  and  repeatedly  referred  to  in  this 
work.  Von  Richthofen's  section  is  quoted  in  volume  I,  page  295.  Above 
the  coal-bearing  middle  Jurassic,  as  determined  by  plant  remains,  come 
coarse  conglomerates,  300  feet,  90  meters,  thick,  followed  by  yellow,  reddish, 
and  finally  greenish  sandstones  about  200  feet,  60  meters,  thick.  The  con- 
glomerates appear  to  mark  an  invasion  of  coarse  material  of  local  origin, 
which  may  be  ascribed  to  increasing  declivities  or  to  greater  precipitation 
in  nearby  mountains.  Together  with  the  overlying  sandstone  it  may  with 
reason  be  referred  to  the  middle  or  upper  Jurassic. 

This  occurrence  is  presumably  typical  for  the  Red  Basin  of  Ssi-ch'uan, 
so  far  as  its  margins  are  concerned.  Although  von  Richthofen  made  more 
extensive  observations  in  this  great  interior  depression  of  western  China 
than  any  one  since,  we  have  no  account  of  them  and  rely  upon  Loczy, 
who  traversed  the  northwestern  margin.  He  states  :§ 

Immediately  upon  the  early  Paleozoic  deposits,  on  the  margin  of  the  basin,  follow 
the  Mesozoic  strata.  In  the  vicinity  of  Ja-ch6u-fu  the  Carboniferous  appears  to  be  wanting, 
as  immediately  beneath  the  Ssi-ch'uan  sandstone  we  found  Devonian  limestone  near 
Hoa-ling-pu.  Near  Kuan-juon,  on  the  other  hand,  the  Carboniferous  and  Permian  strata 
probably  occur  in  the  marginal  mountains,  as  has  been  stated  above. 

The  Mesozoic  systems  are  represented  by  the  great  series  of  the  Ssi'-ch'uan  sandstones. 
This  sandstone  formation  consists  of  red  and  gray  sandstones,  coarse  conglomerates,  and 
marly  shales,  and  in  its  lower  layers  are  huge  coal-beds,  which  are  worked  at  many  points 
about  the  northern  and  western  margins.  The  coal-beds  near  Kuan-juon-shien  and 
Hoani-pu  yielded  impressions  of  plants  of  the  middle  Jura  (Dogger),  whereas  near  Lin- 
tschi-shien  and  Ni-tou  we  collected  Liassic  plants. 

Marine  fossils  are  not  yet  known  from  the  Ssi'-ch'uan  sandstone.  The  only  fragment 
of  a  mollusk  is  a  doubtful  Anoplophora  (Cardinia)  which  was  found  near  Lin-tschi-shien, 
but  it  is  not  sufficiently  well  preserved  to  afford  definite  evidence  for  or  against  a  marine 
origin. 

The  Ssi'-ch'uan  red  series  is  petrographically  as  well  as  geologically  and  structurally 
identical  with  the  red  sandstone  of  the  province  of  Kiang  si,  as  well  as  with  the  basin 
deposits  which  we  saw  on  the  lower  Han-kiang  and  on  the  Si£-ho. 


*  Research  in  China,  vol.  I,  p.  316 
t  China,  vol.  n,  p.  603. 

I  Reise  des  Grafen  Sz£chenyi,  vol.  i,  p.  440. 
§/«<*,  pp.  685-686. 


STRUCTURE   OF  ASIA.  89 


PERMO-MESOZOIC  DIASTROPHISM. 

The  diastrophic  movements  which  occurred  in  all  continents  during 
the  closing  epochs  of  the  Paleozoic  and  the  initial  epochs  of  the  Mesozoic 
were  pronounced  and  prolonged  throughout  Asia.  They  ultimately  changed 
that  face  of  the  globe,  as  Suess  has  pointed  out,*  welding  together  the  sepa- 
rate elements  of  the  Asiatic  continent,  except  that  the  Angara  and  Gond- 
wana  lands  remained  separated  by  the  Himalayan  strait.  In  contrast  to 
the  gradual  changes  of  level  which  had  characterized  the  Paleozoic,  these 
disturbances  were  of  decidedly  orogenic  character.  They  gave  rise  to 
mountain  systems,  which  are  structurally  still  the  controlling  features  of 
Asia.  The  foundations  of  the  ranges  are  now  raised  to  the  summits  of 
the  Tien-shan,  Kuen-lung,  and  Ts'in-ling-shan,  and  the  substance  of  their 
masses  constitutes  the  Triassic  and  Jurassic  sediment  of  Asia.  By  Cre- 
taceous time  the  continent  was  again  low. 

The  continental  structure  of  Asia  has  been  so  elaborately  described 
by  Suess.f  the  master  of  the  subject,  that  extended  discussion  is  superfluous 
unless  based  on  new  data;  and  in  general  such  data  are  not  yet  available. 
Furthermore,  what  later  information  we  have  confirmed  his  deductions,  as 
regards  the  trends  of  mountain  axes.  We  may,  however,  point  out  that 
the  Sinian  is  more  generally  folded  in  North  China  than  von  Richthofen, 
and  consequently  Suess,  supposed.  And  our  observations  give  additional 
data  on  the  structure  of  the  Wu-t'ai-shan,  the  Ts'in-ling-shan,  the  Han 
district,  and  the  middle  Yang-tzi'  region. 

On  the  map,  plate  8,  are  shown  the  structural  lines  given  by  Suess,J 
supplemented  by  those  traced  by  Futterer§  south  of  latitude  36°. 

Referring  to  these  authors  for  their  presentation,  I  proceed  to  discuss 
some  of  the  newer  significant  facts. 

Through  his  reconnaissance  observations  in  Shan-tung  von  Richthofen 
gained  the  impression  that  Sinian  strata  had  not  been  folded,  and  in  pass- 
ing through  the  Wu-t'ai  district  he  was  so  circumstanced  that  he  did  not 
observe  the  actual  facts  of  structure.  Our  observations  in  the  Ch'ang-hia 
district  of  western  Shan-tung  showed  that  the  Sinian  is  folded  and  even 
overthrust,  the  axial  trends  being  dominantly  northeast-southwest  and 
subordinately  north  west-southeast.  ||  And  in  the  Wu-t'ai  district  the 
Sinian  and  Carboniferous  exhibit  overfolds  and  overthrusts  of  a  decided 

*  La  Face  de  la  Terre,  vol.  in,  p.  24. 
t  Ibid.,  vol.  in. 

I  Ibid.,  vol.  in,  pi.  in. 
§Petermanns  Mitt.  Erg.,  Heft  119. 

II  Vol.  i,  chapter  in,  and  plates  xin  and  xv. 


90  RESEARCH   IN  CHINA. 

character,  which  there   extend    northeast  to   southwest,   parallel  to  the 
structure  of  the  pre-Sinian  sediments.* 

To  what  extent  these  structures  are  general  in  North  China  is  not  yet 
determinable.  The  Ch'ang-hia  district  is  a  very  limited  area;  the  folding 
is  moderate  and  probably  local.  The  folds  of  the  Wu-t'ai  district  are  much 
more  pronounced  and  occur  in  a  zone  of  ancient  deformation  which  is  mar- 
ginal to  the  masses  of  Mongolia  and  Ordos.  It  is  traced  from  northern 
Chi'-li  across  Shan-si  to  Shen-si,  a  distance  of  500  miles,  800  kilometers,  and 
is  a  structural  zone  of  the  first  order,  which  is  represented  in  modern  moun- 
tain systems  by  notable  heights.  Southeast  of  it  lies  the  plateau  of  eastern 
Shan-si,  which,  in  the  southern  part  where  von  Richthofen  crossed,  presents 
the  Paleozoic  in  little  disturbed  strata.  It  is  possible,  but  not  known,  that 
no  folds  invade  its  broad  area. 

The  date  of  deformation  in  North  China  is  fixed  as  not  earlier  than 
upper  Carboniferous  (Pennsylvanian)  by  the  parallelism  of  strata  of  that 
age  with  the  Sinian  over  wide  areas,  and  as  pre-Liassic  by  the  unconformity 
which  was  observed  by  von  Richthofen  between  the  Sinian  and  the  Liassic 
coal-measures  of  the  Ta-tung-fu  field  in  northwest  Shan-si.  The  latter 
strata  are  also  tilted,  probably  in  consequence  of  a  recurrent  movement  in 
Jurassic  time. 

As  was  first  pointed  out  by  von  Richthofen,  the  Ts'in-ling-shan, 
the  eastern  continuation  of  the  Kuen-lung  system,  occupies  the  site  of  a 
trough  in  which  Paleozoic  sediments  accumulated  to  considerable  thickness, 
if  the  consensus  of  opinion  regarding  the  age  of  the  metamorphosed  sedi- 
ments be  correct.  Its  folds  embrace  the  southern  margin  of  the  ancient 
land  mass  that  is  now  northern  Shen-si  and  Kan-su.  The  trend  of  the  axes 
of  folding  in  that  part  of  the  range  east  of  longitude  108°  is  not  exactly 
parallel  with  the  modern  height.  Von  Richthofen's  preliminary  map,  a 
bold  essay  on  the  slight  data  available  to  him,  was  mistaken  in  this  respect. 
The  range  trends  about  north  75°  east,  and  the  general  axial  strike  of  the 
structures  varies  from  east-west  to  north  80°  west.  Thus  the  belts  of  the 
Archean,  Proterozoic,  'and  Paleozoic  strata  in  general  approach  the  northern 
front  at  an  angle  and  are  cut  off  by  the  fault,  which  is  the  latest  tectonic 
feature.  The  angle  is  an  acute  one,  and  in  the  case  of  the  contact  of  the 
Proterozoic  and  Paleozoic  south  of  Ch6u-ch'i-hien,  the  line  trends  south  of 
west;  but  the  larger  features  of  the  structure  diverge  from  the  range  and 
pass  under  the  Wei'  valley,  where  they  are  faulted  down. 

The  Ts'in-ling-shan  and  the  mountainous  region  south  of  it,  through 
which  the  Han  flows  from  Han-chung-fu  to  beyond  Hing-an-fu,  was  the 
scene  of  more  or  less  intense  metamorphism  and  intrusion,  as  well  as  of 

*Vol.  I,  chap.  v. 


PERMO-MESOZOIC   INTRUSIONS.  91 

folding.  In  the  section  observed  by  L6czy,  in  longitude  106°  east,  in  that 
previously  observed  by  von  Richthofen  in  longitude  107°  30'  east,  and  in 
that  of  the  expedition  of  1903-04  in  longitude  108°  15'  east,  there  are  areas 
of  slates,  argillites,  schists,  and  gneisses,  apparently  derived  from  Paleozoic 
sediments  and  associated  with  large  masses  of  intrusive  diorite  or  granite. 
In  the  last-named  section  two  large  granite  masses  and  several  smaller  ones 
present  a  total  width  of  19  miles  in  84  miles.  They  are  intrusive  bands, 
whose  length  along  their  trend  parallel  to  the  axis  of  the  range  is  very 
considerable.  Their  effect  in  altering  adjacent  strata  is  extremely  variable, 
the  limestone  of  the  Hei'-shui  series  near  lyiu-yiie-ho  (atlas  sheet  a  2)  being 
but  little  affected  a  hundred  feet  from  the  contact,  whereas  near  Ssi'-mou-ti 
(atlas  sheet  a  3)  the  Paleozoic  strata  are  generally  and  intensely  metamor- 
phosed, although  the  intrusions  as  they  appear  at  the  surface  are  much 
smaller. 

The  date  of  these  intrusions  is  later  than  the  folding,  as  the  holocrys- 
talline  intrusive  rocks  were  not  sheared,  but  it  is  presumably  not  much 
later.  Among  the  intruded  and  metamorphosed  strata  we  believe  we  have 
identified  the  K'ui-chou  formation,  i.  e.,  Permo-Triassic,  which  may  have 
been  contemporaneous  with  the  early  effects  of  deformation,  but  which  was 
involved  in  the  later  effects  to  the  extent  of  overfolding  and  overthrusting. 
And  unconformably  above  the  metamorphosed  strata  occur  the  unaltered 
Shi-ts'uan  sandstones,  which  we  correlate  tentatively  with  the  middle  or 
upper  Jurassic  sandstone  of  the  Red  Basin  of  Ss'i-ch'uan.  These  data  seem 
to  confine  the  episode  of  intrusion  to  the  Triassic  or  early  Jurassic,  to  the 
close  of  the  period  of  diastrophism.  The  inference  is  strengthened  by  the 
fact  that  there  are  not  any  Cretaceous  or  early  Tertiary  sediments  of  marine 
or  continental  character,  such  as  should  occur  as  a  result  of  erosion  if, 
during  those  periods,  there  had  been  great  intrusions  of  granite,  with  the 
probable  accompaniment  of  decided  elevation. 

The  region  within  which  the  early  Mesozoic  intrusions  occur  is  not  yet 
well  defined.  In  the  western  Ts'in-ling-shan,  between  longitudes  107°  and 
1 08°  east,  the  zone  may  be  said  to  extend  from  the  Wei'  to  the  Han  valleys, 
between  latitudes  33°  and  34°  10'  north.  In  longitude  109°  30'  its  southern 
margin  is  near  Chon-p'ing-hie'n,  latitude  31°  50'.  The  eastern  and  north- 
eastern extension  is  indefinite,  as  the  great  granite  masses  of  the  eastern 
Ts'in-ling-shan,  which  may  in  part  belong  to  this  period,  are  described 
by  l,6czy  and  von  Richthofen  as  "Archean."  Toward  the  northwest,  in 
longitude  105°  east,  latitude  35°,  near  "Kun-tschang-fu"  Loczy  *  observed 
intrusions  of  granite  in  mica,  amphibole,  and  chlorite  schists.  The  occur- 
rence is  one  of  many  granite  masses  which  characterize  the  northwestern 

*Reise  des  Grafen  Sz£chenyi,  vol.  I,  p.  425. 


92  RESEARCH   IN   CHINA. 

Ts'in-ling-shan,  and  appear  to  be  part  of  the  zone  under  consideration. 
The  western  continuation  of  the  mountain  system,  the  Nan-shan  ranges, 
was  a  scene  of  igneous  intrusions,  as  described  by  Obrutchov,  but  whether 
of  pre-Cambrian,  middle  Paleozoic,  or  Mesozoic  date  we  can  not  distin- 
guish. In  western  Ssi'-ch'uan,  longitude  99°  to  103°  east,  latitude  30°  north, 
between  Ba-tang  and  Ja-chou  (Ya-chou),  where  Paleozoic  and  Mesozoic 
strata  are  folded  around  the  eastern  margin  of  the  Tibetan  plateau,  Loczy 
observed  great  bodies  of  granite  in  the  metamorphic  schists.  He  com- 
pares the  rocks  with  the  Nan-shan  sandstone,  and  again  we  are  uncertain 
whether  the  intrusions  are  pre-Cambrian  or  Mesozoic.  In  this  connection 
it  is  worth  while  to  point  out  that  the  Ts'in-ling-shan  and  the  Alps  of  west- 
ern Tibet  bound  the  depressed  basin  of  Ssi'-ch'uan  on  the  north  and  west 
and  coalesce  at  its  northwestern  corner.  The  geologic  conditions  which  led 
up  to  the  Permo-Mesozoic  diastrophism  were  identical  in  the  two  belts,  so 
far  as  the  stratigraphic  history  is  concerned;  the  effects  of  folding  appear 
to  have  been  much  the  same;  and  it  is  probable  that  the  phenomena  of 
intrusion  which  affected  the  one  occurred  in  the  other.  The  southern  con- 
tinuation of  the  mountains  of  Ssi'-ch'uan  and  Yiin-nan  extends  through 
Indo-China,  where  Fuchs  and  Saladin  distinguish  an  ancient  granite  and  a 
microgranulite  of  Carboniferous  or  post-Carboniferous  age.*  In  view  of 
the  reconnaissance  nature  of  the  observations  the  age  of  the  ancient  granite 
may  be  considered  undetermined  and  possibly  Mesozoic. 

In  this  connection  it  is  desirable  to  mention  the  fact  brought  out  by 
Haydenf  in  course  of  the  Younghusband  expedition  to  Tibet  that  Jurassic 
and  Cretaceous  strata  of  southeastern  Tibet,  south  of  Lhasa,  are  highly 
metamorphosed  and  intruded  by  granite.  At  first  thought  the  suggestion 
occurs  that  the  post-Cretaceous  age  of  these  intrusions  may  indicate  a  like 
recency  for  the  intrusions  of  the  Ts'in-ling-shan;  but  the  unaltered  char- 
acter of  the  supposed  Jurassic  in  that  region  appears  to  preclude  the  idea; 
and  it  is  more  likely  that  the  events  in  the  Ts'in-ling-shan  and  in  south- 
eastern Tibet  are  successive  than  that  they  were  contemporaneous. 

In  strong  contrast  to  the  pronounced  folding,  metamorphism,  and 
intrusion  that  characterize  the  central  Ts'in-ling-shan  and  the  Han  valley 
is  the  moderate  deformation  of  the  region  on  the  south.  Folded  Paleozoic 
strata,  which  are  indeed  closely  folded  and  even  overthrust,  but  not  altered, 
adjoin  the  metamorphic  district  along  a  remarkably  sharp  boundary,  and 
pass  into  the  wide  flexures  of  the  middle  Yang-tzi'  or  the  synclinorium  of 
the  Red  Basin.  On  the  Yang-tzi'  there  is  complete  conformity  of  dip  up  to 
and  including  the  K'ui-ch6u  beds  (Rhaetic).  About  the  Red  Basin  there 

*Annales  des  Mines,  1882,  8me  serie,  Memoires  2,  pp.  224-225. 
f  Report  Geol.  Sur.  of  India,  1905. 


DURATION   OP  FOLDING.  93 

are  unconformities.  That  near  Kuan-yiian-hien  is  overlain  by  limestone 
which  may  be  Permian  or  Rhaetic,  as  already  stated.  But  west  of  Ja-chou* 
the  Mesozoic  sediments  are  conformable  to  the  underlying  Devonian  and 
are  folded  with  it.  Hence  Loczy  infers  that  the  folding  continued  longer  in 
the  latter  region.  It  is  possible  that  the  vicinity  of  Ja-chou  was  outside  the 
zone  of  Permo-Mesozoic  folding,  as  most  of  the  Red  Basin  was,  and  became 
involved  in  disturbance  only  when  the  Himalayas  were  compressed  in  the 
great  post-Eocene  epoch  of  diastrophism.  In  the  zone  of  the  great  mountain 
chains  of  northern  India,  the  Permo-Mesozoic  movement  was  manifested 
only  in  variations  of  sediment,  not  in  folding. 

*Reise  des  Grafen  Sz^chenyi,  L6czy,  vol.  I,  p.  690. 


CHAPTER  VII.— CONTINENTAL  ASIA. 


CRETACEOUS. 

A  geologist  taught  only  by  observation  in  China,  outside  of  Tibet, 
would  know  nothing  of  the  Cretaceous.  No  strata  are  known  which  may  be 
correlated  with  the  strata  that  represent  the  period  in  America  and  Europe. 
We  would  look  for  marine  or  continental  deposits  in  the  middle  Yang-tzi 
region  or  the  Red  Basin  of  Ssi-ch'uan,  where  they  might  cap  the  Jurassic 
in  the  deeper  synclines;  or  about  the  margins  of  the  great  alluvial  plain  of 
the  Yang-tzi  and  the  Huang-ho,  where  they  might  outcrop  in  the  foothills; 
but  they  are  not  found.  If  they  ever  existed  above  the  known  Jurassic  they 
have  been  eroded;  if  they  underlie  the  plain  they  are  overlapped. 

Nor  are  Cretaceous  strata  of  any  kind  known  in  the  vast  area  of  Asia 
north  of  Tibet,  east  of  the  Urals,  and  south  of  northern  Siberia.  No  other  fact 
than  this,  perhaps,  more  sharply  challenges  the  hypothesis  that  the  present 
mountain  ranges  and  basins  of  central  Asia  date  from  a  pre-Cretaceous 
time.  Highlands  without  waste  and  waste  without  deposit  in  these  interior 
basins  are  inconceivable;  but  though  the  plateaus  are  affected  by  post- 
Cretaceous  dislocations  which  expose  even  the  ancient  crystallines,  there 
is  no  trace  of  deposition  during  the  Cretaceous  period.  The  surface  that 
could  for  so  long  a  time  maintain  a  blank  record  must  have  been  a  land 
in  which  transportation  and  aggradation  had  ceased  in  consequence  of 
uniformity  and  flatness  of  slope — a  well-developed  peneplain.  Even  on 
such  a  surface  subaerial  decay  must  produce  residual  material  and  the 
atmosphere  do  some  work;  but  the  product  might  be  worked  over  into 
later  deposits,  as  it  probably  has  been. 

Some  of  the  waste  from  this  Cretaceous  land  found  its  way  into  the 
southern  Tethys,  where  it  formed  the  Giumal  sandstone.  The  area  of 
deposition  extends  throughout  the  Himalayas,  over  southern  Tibet,  and 
through  Kashmir  into  Afghanistan  and  Persia.* 

The  rock  is  a  greenish-gray  sandstone,  sometimes  very  siliceous,  and 
of  considerable  thickness.  There  is  a  transition  to  it  from  the  underlying 
Jurassic  shales,  and  it  is  separated  by  a  sharp  but  conformable  contact  from 
the  overlying  upper  Cretaceous  limestone,  which  extensively  overlaps  it. 
Thus,  in  the  latest  Jurassic,  lower  Cretaceous,  and  upper  Cretaceous  of 

*Griesbach:  Memoirs  G.  S.  I.  xxin,  p.  81. 

95 


96  RESEARCH   IN   CHINA. 

northern  India  we  have  the  sedimentary  record  of  the  reduction,  peneplana- 
tion,  and  partial  submergence  of  the  continent,  which  in  preceding  Mesozoic 
time  had  attained  very  prominent  relief. 

TERTIARY  AND  QUATERNARY. 

A  sedimentary  record  of  the  Tertiary  history  of  China  is  wanting,  as 
is  that  of  the  Cretaceous.  We  turn  to  Indo-China,  India,  southern  Tibet, 
and  western  Asia,  for  occurrences  of  marine  and  estuarine  deposits,  which 
by  their  calcareous  or  carbonaceous  character  show  that  the  peneplain 
conditions  of  the  Cretaceous  period  were  continued,  at  least  in  southern 
Asia,  through  the  Eocene  and  Oligocene  and  well  into  the  Miocene.  The 
marine  zone  which  was  the  southern  branch  of  the  Tethys  persisted  along 
the  Himalayan  region  and  still  divided  the  ancient  Gondwana  land  of  the 
Indian  peninsula  from  Tibet.  The  movements  which,  during  the  Oligocene 
and  Miocene,  closed  the  strait,  are  described  by  Griesbach,*  who,  in  a  lim- 
ited exploration  of  the  Hundes  plateau  of  southern  Tibet,  distinguished 
altered  nummulitic  limestone,  unconformably  overlain  by  Miocene  (?)  sand- 
stone, a  few  hundred  feet  thick,  which  in  turn  is  conformably  covered  by 
a  great  thickness  of  nearly  horizontal  beds  that  Lydekker  determined  on 
the  evidence  of  mammalian  bones  to  be  probably  Pleistocene  and  certainly 
not  older  than  Pliocene.  The  recent  observations  by  Hayden  in  the  prov- 
ince of  Tsang  and  U  along  Younghusband's  route  to  Lhasa  have  confirmed 
Griesbach 's  observations.! 

The  evidence  of  stratigraphy  north  of  the  range  agrees  with  that  of 
the  Siwaliks  of  the  southern  foothills,  and  there  is  every  reason  to  accept 
Oldham's  view  that  much  of  the  elevation  of  the  Himalayas  has  occurred 
since  the  Miocene  epoch. $  In  view  of  the  evidence  that  other  mountain 
systems  of  Asia  have  grown  to  great  heights  during  the  Pleistocene  it  may 
be  questioned  whether  the  Himalayas  reached  their  present  altitude  during 
the  initial  movements  of  folding ;  it  is  even  probable  that  they  have  suffered 
one  partial  epoch  of  erosion  to  advanced  maturity  and  have  since  been 
warped  up,  as  have  the  Apennines  and  Karpathians;§  but  they  in  any 
case  represent  the  latest  effects  of  the  compressive  force  which  has  welded 
Asia  into  a  continent. 

History  repeats  itself,  now  here,  now  there.  The  northern  Tethys 
was  closed  by  a  late  Carboniferous  movement,  during  which  the  Kuen-lung 
system  of  folds  developed;  and  the  supra-Carboniferous  sandstones  were 

*Central  Himalayas,  Memoirs  G.  S.  I.  xxm,  pp.  82-87. 

fGeology  of  Tibet,  Rec.  G  S.  I.,  1905. 

J  Manual  of  Geology  of  India,  second  edition,  1893,  p.  479. 

§  Studies  in  Europe,  B.  Willis,  Year  Book  of  the  Carnegie  Institution  of  Washington  No.  4. 


CONTINENTAL  DEPOSITS.  97 

spread  upon  the  flanks.  The  strata  that  form  the  Ts'in-ling-shan  and  the 
Alps  of  western  Tibet  shared  in  the  Kuen-lung  movement,  but  they  also 
suffered  a  later  intense  disturbance,  which  gave  rise  to  the  erosion  cycle 
that  is  represented  in  the  Jurassic  sandstones.  And  the  Himalayan  zone, 
which,  until  post-Eocene  time  had  not  been  folded,  then  became  the  locus 
of  pronounced  deformation  and  passed  through  the  movements  that  are 
evidenced  by  the  unconformities  and  sediments  of  the  Tertiaries.  Loczy 
noted  that  the  Jurassic  beds  of  Ssi'-ch'uan  and  the  supra-Carboniferous  of 
central  Asia*  are  similar  products  of  vigorous  erosion  of  mountain  ranges 
that  were  elevated  at  separate  times;  and  we  may  add  the  Hundes  and 
Siwalik  sandstones  as  a  third  group  of  formations  of  the  same  kind. 

With  the  epoch  of  mid-Tertiary  folding  the  compression  of  Asia  ceased 
for  a  time  at  least.  The  flat  Hundes  sandstone  has  its  equivalents  in  the 
essentially  flat  Pliocene  and  Pleistocene  deposits  of  central  Asia  and  Siberia. 
The  record  is  one  of  erosion  and  wide-spread  deposition  in  basins,  either 
lacustrine  or  arid,  and  on  fluviatile  plains.  But  diastrophic  movements 
have  not  ceased ;  they  have  taken  on  the  form  of  normal  faulting,  involved 
in  spreading  of  the  continent,  and  the  major  features  are  accented  by  the 
fractures.  These  phenomena,  which  are  extreme  effects  of  vertical  warp- 
ing, are  chiefly  of  Pleistocene  age. 

I  proceed  to  consider  the  evidence  of  orogenic  movements  other  than 
folding;  it  is  subordinately  stratigraphic  and  predominantly  physiographic. 

Before  considering  the  Quaternary  warping  it  is  well  to  describe  in 
proper  sequence  the  Tertiary  dislocations  of  the  same  type.  In  north- 
eastern China,  in  the  provinces  of  Shan-tung  and  Chi-li,  are  two  districts  in 
which  normal  faulting  is  the  principal  structural  fact.  They  have  been 
mapped  and  described  in  volume  I,  so  far  as  we  saw  them;  and  we  have 
there  cited  observations  by  von  Richthofen,  who  noted  the  faults  of  Shan- 
tung as  the  principal  structural  facts  of  that  province.  The  district  in 
Chi'-li  is  that  which  we  call  the  Ning-shan  basin,  west  of  Pau-ting-fu,  and 
has  not  been  seen  by  any  other  geologists. 

The  evidence  of  faulting  in  these  cases  is  chiefly  stratigraphic:  Paleo- 
zoic faulted  down  in  contact  with  Archean,  along  throws  which  range  up  to 
10,000  feet,  3,000  meters,  or  more;  but  in  Shan-tung  the  relief  due  to  dis- 
placement still  survives,  though  it  is  greatly  dissected.  Fault-scarps  have 
receded  one  or  two  miles;  fault-blocks  are  cut  into  isolated  sections  by  the 
valleys  of  consequent  streams  that  originated  on  the  scarps;  valleys  have 
widened  and  mountain  masses  have  become  skeletonized.  The  volume  of 
rock  removed  is  very  large,  but  since  the  districts  have  had  open  drainage 
to  areas  now  submerged  or  buried  beneath  recent  alluvium,  there  are  no 

*  Reise  des  Grafen  Szcdienyi,  vol.  I,  p.  799. 


98  RESEARCH   IN   CHINA. 

accessible  deposits  corresponding  to  the  cycle  of  erosion.  We  are  thus 
restricted  to  physiographic  evidence  in  seeking  to  date  the  epoch  of  faulting, 
but,  by  comparing  the  effects  of  erosion  with  those  accomplished  elsewhere 
since  the  middle  Tertiary,  we  reach  a  probable  conclusion  that  the  time  was 
pre-Miocene. 

In  the  Ning-shan  district  of  Chi'-li  the  relief  due  to  faulting  no  longer 
survives;  indeed  it  has  been  reversed,  limestone  hills  on  the  downthrow 
rising  1,000  feet,  300  meters,  above  the  surface  of  gneiss  on  the  upthrow. 
Hence  we  infer  that  the  faulting  may  be  somewhat  older  than  that  in  Shan- 
tung, and  we  place  it  in  the  earliest  Tertiary. 

The  faulted  district  of  western  Shan-tung  and  that  of  Ning-shan  in 
Chi-li  are  isolated  occurrences  in  eastern  Asia,  so  far  as  we  now  know,  of 
dislocations  of  early  Tertiary  age.  Yet  it  is  probable  that  they  are  not 
singular,  and  anticipating  somewhat  the  discussion  of  physiographic  cycles 
which  follows,  it  is  desirable  to  state  in  this  connection  the  conclusion 
reached  by  Suess,  that  the  profound  graben  which  is  occupied  by  Lake  Bai- 
kal has  existed  since  the  close  of  the  Tertiary  period.*  The  evidence,  which 
consists  of  the  survival  of  species  of  European  Pliocene  affinities  in  the  lake, 
is  clearly  assembled,  and  the  age  of  the  basin  appears  well  established.  The 
depression  is  due  to  normal  faults,  which  define  the  graben  and  which  are 
paralleled  by  others  that  give  rise  to  the  ranges  of  Trans-Baikalia.  Attrib- 
uting to  the  system  the  age  determined  for  the  lake  basin,  we  recognize 
in  Trans-Baikalia  a  mountain  group  of  late  Tertiary  date. 

It  will  be  seen  by  reference  to  volume  i,  that  the  faults  which  charac- 
terize the  Ki-chou-shan,  Ho-shan,  Hua-shan,  and  Ts'in-ling-shan,  all  of 
which  are  mountain  ranges  in  Shan-si  and  Shen-si,  China,  are  referred  to  a 
Quaternary,  probably  middle  and  late  Quaternary,  date.  Hence,  taking 
accpunt  of  the  Chi-li,  Shan-tung,  Baikal,  and  Shan-si  fault-systems,  I  con- 
clude that  normal  faulting  has  been  a  feature  of  orogenic  activity  in  Asia, 
in  one  district  or  another,  since  early  Tertiary  time. 

Warping,  that  is,  nearly  vertical  displacement  of  different  parts  of  the 
surface  to  unequal  amounts  and  often  in  opposite  directions  without  dislo- 
cation, has  been  a  general  effect  of  diastrophism,  especially  during  the  later 
Tertiary  and  Quaternary.  And  the  displacements  have  been  so  conditioned 
in  time  and  place  as  to  give  rise  to  cycles  of  erosion,  which  can  be  distin- 
guished in  the  plains,  plateaus,  ranges,  and  rivers  of  the  continent.  They 
have  been  described  in  the  physiographic  study  of  the  districts  through 
which  we  passed,  as  presented  in  volume  i.  There  the  surface  is  analyzed, 
the  development  of  streams  is  traced,  and  the  interaction  of  diastrophic 

*  La  Face  de  la  Terre,  vol.  in,  p.  78. 


PHYSIOGRAPHIC  STAGES.  99 

movements  with  erosion  is  presented.     The  climatic  factor  is  also  recog- 
nized and  applied  to  aid  in  fixing  the  date  of  initial  loess  deposition. 

Four  phases  are  distinguished :  the  first  or  oldest  is  a  peneplain,  a  very 
ancient  and  also  very  aged  form,  which  is  known  from  various  parts  of 
northern  Asia,  and  a  remnant  of  which  we  named  from  its  preservation  in 
the  highest  dome  of  the  Wu-t'ai-shan,  the  Pei-t'ai  form,  developed  during 
the  Pei-t'ai  cycle. 

The  next  younger  is  a  surface  of  mature  erosion,  which  replaced  any 
older  features  in  most  of  the  areas  we  saw.  It  is  a  surface  of  moderate 
relief,  characterized  by  wide  valleys  and  hills  rarely  a  thousand  feet  high. 
It  is  typically  developed  near  T'ang-hien,  Chi'-li,  and  we  call  it  the  T'ang- 
hien  stage. 

The  third  phase  was  one  of  aggradation  in  North  China,  the  time  of  the 
early  loess  deposits.  The  moderate  relief  of  the  preceding  stage  was  to  a 
notable  extent  buried  beneath  the  Huang-t'u,  a  formation  consisting  of 
wind-sorted  waste  from  the  deserts  of  central  Asia,  whence  the  dust  was 
brought  chiefly  by  rivers.  The  partly  buried  hills  along  the  western  mar- 
gin of  the  Great  Plain  of  eastern  China  afford  an  illustration  of  the  aspect 
of  Chi'-li,  Shan-si,  and  northern  Shen-si  at  the  time.  The  great  mountain 
ranges  had  not  attained  their  present  height.  Attributing  the  desert  waste 
to  the  climatic  change  from  Tertiary  to  Pleistocene,  which  may  have 
become  effective  in  late  Pliocene  to  the  extent  observed,  we  assign  this 
phase  to  that  time  and  to  the  opening  of  the  Pleistocene.  We  designate  it 
the  Hin-chou  stage,  after  the  Hin-chou  loess  basin  in  Shan-si. 

The  fourth  and  present  physiographic  stage  we  named  for  North  China 
the  Fon-ho,  from  the  river  of  that  name,  which,  though  older  than  the  Fon- 
ho  epoch,  still  flows  through  Shan-si  among  characteristic  features  of  that 
stage.  For  South  China,  where  the  physiographic  relations  are  somewhat 
different,  we  applied  the  name  Yang-tzi  to  what  is  very  nearly  or  precisely 
the  same  time  division.  It  is  an  epoch  of  very  decided  mountain  growth  in 
China;  and  if,  as  I  believe,  the  principal  continental  upwarp  of  central  Asia 
is  largely  of  the  same  date,  it  is  the  time  of  one  of  the  most  remarkable 
diastrophic  movements  of  which  we  have  knowledge.  It  appears  to  fall 
chiefly  within  the  Quaternary,  but  may  extend  back  into  the  Pliocene. 
The  typical  features  are  warped  and  faulted  surfaces,  which  result  from 
downward  and  upward  movements  of  adjacent  masses  that  underlie  basins 
and  graben  or  constitute  plateaus  and  mountain  ranges.  The  amount  of 
sculpture  is  relatively  slight,  but  great  canyons  like  the  Yang-tzi  gorges  have 
been  cut  by  antecedent  rivers. 

Having  thus  summarized  the  results  of  our  observations  in  China,  I 
suggest  their  broader  relations. 


100  RESEARCH   IN  CHINA. 

The  oldest,  the  Pei'-t'ai  cycle,  links  the  physiographic  history  with  the 
stratigraphic  record.  We  have  seen  that  in  the  sediments  there  is  reason  to 
regard  the  Cretaceous  as  a  time  when  Asia  presented  the  aspect  of  an  exten- 
sive peneplain,  over  which  the  sea  transgressed  from  the  south.  Sediments 
of  the  Eocene  and  Oligocene  epochs  record  the  same  conditions.  We  regard 
the  Pei'-t'ai  as  the  equivalent  surface,  and  the  Pei'-t'ai  cycle  as  covering  late 
Cretaceous  and  early  Tertiary.  It  is  the  Asiatic  representative  of  the 
Schooley  or  Kittatinny  peneplain  of  the  eastern  United  States  and  of  the 
Cretaceous  peneplain  of  central  Europe. 

The  remnant  of  a  peneplain  which  we  recognized  in  Pe'i-t'ai  by  its  form 
and  by  the  residual  soil  peculiar  to  it,  is  of  very  small  extent,  and  we  may 
well  ask  what  other  evidences  remain  to  support  the  inferences  of  a  once 
general  condition.  Let  us  proceed  northeastward  from  the  Wu-t'ai-shan, 
which  is  in  northern  Shan-si,  and  review  some  known  features,  bearing  in 
mind  that  the  ancient  surface  is  both  warped  and  eroded;  consequently 
it  may  occur  at  any  altitude  and  may  be  more  or  less  dissected.  Where 
the  Siberian  railroad,  after  leaving  the  dislocated  mountainous  region  of 
Trans-Baikalia,  traverses  northeastern  Mongolia  to  the  Khingan  range  and 
descends  into  the  valleys  of  Manchuria,  there  is  a  plateau  surface  which 
is  a  slightly  warped  plain  of  erosion,  occasionally  capped  by  lava  flows.  In 
the  Khingan  range  it  is  warped  a  few  hundred  feet  higher  and,  extending 
over  the  crest,  is  represented  in  the  summits  of  the  long  spurs  which  consti- 
tute the  deeply  canyoned  eastern  slope.  In  Manchuria  it  sinks  beneath 
the  alluvium  of  the  Sungari,  as  the  tilted  peneplain  that  forms  the  western 
slope  of  the  Sierra  Nevada  of  California  sinks  beneath  the  alluvium  of  the 
Sacramento. 

Suess  refers  to  the  eastern  slope  of  the  great  Khingan  range  in  its  north- 
ern extension  as  being  analogous  to  a  flexure,  and  gives  the  following  account 
of  the  great  plain  of  the  Amur  :* 

The  constitution  of  the  plain  which  extends  northward  from  the  upper  Amur  is  not 
altogether  simple.  Even  at  the  eastern  base  of  the  Khingan,  beds  of  the  Angara  series 
appear  *  *  *  and  occupy  all  the  west  of  the  plain  *  *  *.  They  are  covered 
by  white  sands  and  shales  with  lignite  of  Tertiary  age,  which  occupy  the  eastern  portion 
of  the  plain  as  far  as  the  Zeia  river  *  *  *.  But  this  mantle  of  Tertiary  has  in  general 
only  a  slight  thickness;  beneath  it  appear,  as  upon  the  upper  Tygda,  the  Archean  rocks 
which  play  scarcely  any  orographic  role.  *  *  *.  In  the  occasional  outcrops  of  the 
Archean  basement  M.  Ivanov  recognized  the  general  strike  of  north-northeast,  but  accord- 
ing to  this  observer  the  Angara  strata  which  form  the  western  part  of  the  plain  are  not 
horizontal;  on  the  contrary,  along  the  Amur,  in  the  strip  between  the  great  Khingan  and 
the  first  outcrops  of  the  Archean  basement,  they  appear  folded  with  the  same  north-north- 
east strike.  The  plain  owes  its  origin  to  the  degradation  of  these  folds. 


*La  Face  de  la  Terre,  vol.  m,  p.  155. 


PEI-T'AI  PLAIN  IN  SIBERIA.  IOI 

This  description  gives  definite  information  regarding  the  occurrence 
of  a  peneplain  which  is  clearly  older  than  the  Tertiary  deposits  which  cover 
it,  and  may  fairly  be  correlated  with  the  Pe'i-t'ai  plain. 

With  reference  to  the  mountains  which  lie  north  of  the  Amur  between 
longitude  120°  and  140°  east,  and  which  are  known  as  the  Aldan  or  Stanovoi 
range,  Suess  quotes  Krapotkin  as  saying,  "That  the  supposed  continuous 
chain  of  the  Stanovoi  range,  serving  to  divide  the  waters  of  the  Arctic  ocean 
from  those  of  the  Pacific,  does  not  exist,  whether  one  thinks  of  it  as  high 
or  low,  abrupt  or  flattened."* 

And  again,  referring  to  the  Vitim  plateau,  which  is  north  of  the  ranges 
of  Trans-Baikalia,  between  1 10°  and  120°,  he  quotes  Krapotkin  to  the  effect 
that  over  a  great  distance  the  country  has  lost  all  individuality. 

The  travelers  who  have  there  sought  to  follow  the  line  dividing  the  two  slopes  have 
not  discovered  a  long  and  continuous  mountain  chain,  but  have  found,  on  the  contrary, 
virgin  forest,  rocks  covered  with  moss,  and  vast  swamps  interrupted  here  and  there  by 
lakes. 

The  region  thus  described  is  connected  by  a  long  slope  with  the  plain 
of  the  Amur,  and  descends  on  the  northwest  to  the  great  plateau  of  horizon- 
tal Paleozoic  rocks  in  which  the  I/ena  has  sunk  its  modern  canyon.  There 
can  be  little  doubt  that  the  vast  expanse  of  plateau  and  plain  in  northern 
Siberia,  from  the  range  of  the  Verkojansk  mountains  on  the  east  to  the 
recent  alluvium  of  the  Ob  on  the  west,  is  a  great  peneplain  like  that  of  the 
Canadian  highlands  of  North  America;  and  traced  as  it  is  by  the  unbiased 
observations  of  Krapotkin,  Ivanov,  and  other  observers,  to  a  position 
beneath  the  Tertiaries  of  the  Amur  basin,  it  may  well  be  assigned  to  an 
early  Tertiary  and  Cretaceous  epoch. 

I  have  seen  the  representative  of  this  peneplain  in  the  vicinity  of  Kras- 
noyarsk, where  it  forms  the  summit  of  the  hills  that  bound  the  valley  of  the 
Jenissei',  and  observed  it  in  the  foothills  of  the  northern  Altai  as  far  as 
Irkutsk.  From  the  railroad  train  one  can  see  the  long  line  of  the  old  topo- 
graphic surface  rising  higher  and  higher  in  the  mountains  toward  the  south, 
and  an  observer  familiar  with  the  features  and  interpretation  of  the  Appa- 
lachian mountains  can  not  doubt  that  he  has  here  in  northern  Asia  a  warped 
peneplain,  which,  like  the  Schooley  peneplain,  is  somewhat  extensively 
dissected. 

The  preceding  observations  may  all  of  them  be  said  to  be  marginal  to 
the  great  highlands  of  central  Asia,  and  although  the  Pei'-t'ai  surface  lies 
at  an  altitude  of  10,000  feet,  3,000  meters,  it  may  be  considered  a  daring 
proposition  to  extend  an  inference  regarding  the  peneplain  to  the  highest 

*  La  Face  de  la  Terre,  vol.  HI,  p.  145 


IO2  RESEARCH   IN   CHINA. 

plateaus  of  the  world.  But  we  need  not  rest  upon  mere  inference.  Davis 
has  described  the  summit  character  of  the  various  ranges  of  the  Tien-shan.* 
He  says: 

Certain  observations  made  in  the  central  and  northern  ranges  [of  the  Tien-shan]  near 
lakes  Son-kul  and  Issak-kul,  and  on  the  steppes  that  border  the  mountains  on  the  north, 
led  to  the  belief  that  the  region  had  been  very  generally  worn  down  to  moderate  or  small 
relief  since  the  time  of  greater  deformation,  which  probably  occurred  in  the  Mesozoic  age ; 
that  large  areas  of  subdued  or  extinguished  mountain  structures  are  still  to  be  seen  in 
the  low  ranges  and  in  the  steppes  north  of  the  Hi  river,  and  that  the  present  relief  of 
many  of  the  higher  Tieii-shan  ranges  is  the  result  of  a  somewhat  disorderly  uplift  and  of  a 
more  or  less  complete  dissection  of  dislocated  parts  of  the  worn-down  region.  Mr.  Hunt- 
ington's  report  shows  the  application  of  these  conclusions  to  a  large  part  of  the  central  and 
southern  Ti£n-shan. 

We  have  no  direct  evidence  of  the  age  of  this  peneplain,  which  is  now 
elevated  to  altitudes  approaching  14,000  feet,  4,200  meters,  but  the  perfec- 
tion of  the  profile  of  the  Bural-bas-tau  and  other  ranges  sketched  by  Davis 
suggest  that  they  have  not  long  been  exposed  in  their  present  altitude. 
And  when  we  consult  the  geologic  section  of  the  adjacent  region  of  western 
Turkestan,  we  find  no  record  earlier  than  the  middle  Tertiary  of  volumi- 
nous deposition,  such  as  the  mountains  are  capable  of  yielding. 

The  descriptions  of  Mongolia  and  northern  Tibet  give  the  physiog- 
rapher no  reason  to  expect  that  an  ancient  topographic  surface  may  there 
survive.  Much  of  the  region  is  buried  beneath  Pliocene  and  Quaternary 
sediments,  and  the  deeply  sunken  surface  of  the  hard  rocks  is  hidden  from 
view.  The  mountain  ranges  which  rise  above  the  sands  have  been  sharply 
sculptured  and  appear  to  be  the  skeletonized  edges  of  warped  and  tilted 
blocks.  While  it  is  possible  that  Davis's  observations  of  the  Tien-shan 
may  be  repeated  elsewhere  in  the  Kuen-lung  or  the  Nan-shan,  it  is  more 
probable  that  our  own  experience  in  the  southeastern  extension  of  these 
ranges,  the  Ts'in-ling-shan,  will  be  paralleled,  and  that  the  observer  will  be 
able  to  recognize  nothing  older  than  a  mature  surface  of  late  Tertiary  date. 

When  we  consider  that  physiographic  studies  have  been  applied  to  the 
interpretation  of  the  features  of  Asia  only  within  the  last  three  years,  it 
arouses  some  surprise  to  find  so  much  evidence  of  a  surviving  peneplain; 
but  that  evidence  appears  to  deserve  frank  recognition  in  view  of  the  series 
of  events  leading  up  to  the  early  Tertiary,  the  stratigraphic  record  of  the 
Cretaceous  and  Tertiary,  and  the  character  of  plateaus  and  plains  of  denu- 
dation which  so  much  of  the  land  presents,  even  at  high  altitudes. 

It  is,  however,  improbable  that  an  entire  continent  of  such  extent  as 
Asia  should  be  completely  peneplained.  In  America  the  peneplanation 
of  the  Cretaceous  period  failed  to  reduce  the  Unaka  mountains  of  North 

*  Explorations  in  Turkestan,  Carnegie  Institution  of  Washington  Publication  No.  26,  p.  72. 


PHYSIOGRAPHY   AND   I,OESS.  IO3 

Carolina*  and  the  case  being  considered  generic  it  was  proposed  that  an 
extended  group  of  heights  surviving  above  a  peneplain  should  be  called  a 
"unaka."  It  is  highly  probable  that  one  or  more  unakas  will  be  found  in 
Asia. 

The  dissection  of  the  Pei'-t'ai  peneplain  (using  that  name  tentatively 
as  a  general  term)  has  proceeded  differently  in  different  regions.  Where  the 
plain  is  buried  beneath  Tertiary  deposits,  as  on  the  Amur,  it  may  be  said 
to  be  intact.  Where  it  has  been  slightly  warped  or  elevated  to  a  moderate 
height  over  vast  areas,  as  in  northern  Siberia,  it  is  still  clearly  recogniz- 
able in  the  featureless  plateaus.  It  may  also  be  seen  as  a  general  line  of 
some  mountain  profiles  where  its  surface  is  more  steeply  tilted,  as  in  the 
northern  Altai.  It  is  found  as  a  mere  remnant  in  such  summits  as  the 
Bural-bas-tau  and  Pei-t'ai.  It  is  no  longer  to  be  seen  in  districts  such  as 
Shan-tung,  where  early  Tertiary  faulting  gave  rise  to  acutely  accented 
relief;  nor  in  the  Ts'in-ling-shan,  where  warping  in  mid-Tertiary  time 
occasioned  the  development  of  a  mature  but  hilly  landscape. 

Throughout  North  China  we  can  distinguish  three  phases  of  physio- 
graphic development  later  than  the  Pei'-t'ai  plain:  the  T'ang-hien,  one  of 
mature  erosion;  the  Hin-chou,  one  of  aggradation;  and  the  Fon-ho,  one  of 
mountain  growth.  In  central  China  we  recognized  but  two:  the  Ts'in-ling, 
which  corresponds  to  the  first  two;  and  the  Yang-tzi,  which  is  probably 
closely  equivalent  to  the  Fon-ho. 

The  distinction  between  the  T'ang-hien  and  the  Hin-chou  epochs 
depends  upon  the  accumulation  of  the  early  deposits  of  loess,  which  covered 
a  vast  area,  but  an  area  conditioned  by  depression  and  geographic  position 
with  reference  to  streams  flowing  from  the  basins  of  central  Asia.  These 
conditions  were  by  no  means  universal ;  they  were  bounded  on  the  south  by 
the  hill  district  of  the  Ts'in-ling-shan;  and  it  is  probable  that  outside  the 
region  of  their  extent  the  distinction  between  the  epochs  can  not  be  made. 
The  equivalent  phase  of  mature  topography,  which  we  have  called  the  Ts'in- 
ling  phase,  will  then  be  found  where  any  feature  older  than  the  Fon-ho  or 
Yang-tzi'  stage  is  recognizable. 

The  Ts'in-ling  stage  of  topographic  development  characterizes  the  sum- 
mit views  of  the  Ts'in-ling-shan,  the  mountains  of  the  Han  valley,  and  the 
ranges  of  the  middle  Yang-tz'i  region,  where  we  traversed  them  from  the 
Wei  valley  to  I-chang  on  the  Yang-tzi'.  It  is  marked  by  more  or  less  decided 
mature  relief,  above  well-developed  valley  floors,  in  which  the  younger 
canyons  are  cut.  It  presumably  succeeds  the  Pei-t'ai  peneplain,  though  the 
earlier  existence  of  the  latter  in  this  region  can  not  be  demonstrated,  since 
erosion  progressed  too  far  in  the  Ts'in-ling  cycle.  It  certainly  replaces  the 
tectonic  relief  which  resulted  from  the  Permo-Mesozoic  folding. 

*Geomorphology  ai  the  Appalachians,  Hayes  and  Campbell,  Nat.  Geog.  Soc.  Mag.,  vol.  vi,  p.  63, 1894. 


IO4  RESEARCH   IN  CHINA. 

The  last  statement  runs  contrary  to  the  views  of  many  geologists,  and 
particularly  to  the  views  of  those  who  hold  with  the  master,  Suess,  that  the 
present  mountain  ranges  are  a  direct  consequence  of  the  compressing  forces 
that  folded  the  strata  within  them.  There  are,  indeed,  two  distinct  points 
of  view,  each  of  which  is  the  outcome  of  observation  in  a  region  that  by  its 
special  character  determines  the  inference.  With  a  few  exceptions,  Euro- 
pean geologists  are  dominated  by  the  stupendous  structures  of  the  Alps,  and 
have  neglected  physiographic  studies.  American  observers  twenty  years 
ago  discovered  a  new  line  of  interpretation  in  physiography,  and  applying 
it  first  to  the  Appalachians  have  since  extended  it  to  other  ranges  and  con- 
tinents. In  the  light  of  present  knowledge  it  appears  safe  to  generalize  as 
follows:  Those  mountain  chains  which  exhibit  folded  stmctures  of  post-Eocene 
development  owe  their  elevation  in  part  possibly  to  the  original  effects  of  that 
compression,  and  in  part  to  subsequent  efforts  of  a  force  acting  in  the  same 
sense,  but  producing  upwarps  and  downwarps  that  are  independent  of  anti- 
clines and  synclines,  yet  related  in  general  position  and  trend  to  the  folded 
chain  as  a  whole.  On  the  other  hand,  altitudes  due  to  folded  structures  of  the 
Permo-Mesozoic  or  older  epochs  of  diastrophism  were  long  since  planed  away 
by  erosion,  and  though  the  structures  may  be  involved  in  relatively  modern 
upwarps,  they  are  not  related  to  the  existing  elevation.  This  is  true  in 
spite  of  the  general  fact,  inherent  in  the  broader  continental  and  oceanic 
features  of  the  earth,  that  some  zones  of  orogenic  activity  retain  their 
dynamic  character  from  an  early  geologic  date  to  the  present,  as  witness 
the  Wu-t'ai-shan. 

There  are  thus  two  types.  Of  the  former,  characterized  by  post- 
Eocene  folding  and  later  warping  in  the  same  sense,  the  Karpathians 
are  the  best  known  example,*  the  structure  and  physiography  of  the  Alps 
being  too  obscure  to  serve  as  a  type.  The  second,  characterized  by  Permo- 
Mesozoic  folding,  peneplanation,  and  relatively  recent  warping,  is  repre- 
sented by  the  classic  Appalachians. 

In  a  region  where  the  relief  is  directly  due  to  anticlinal  elevations  and 
synclinal  depressions  the  relation  between  the  altitudes  and  the  structures 
must  be  such  that  the  anticlinoria  at  least  correspond  to  heights  and  the 
synclinoria  to  lows.  A  case  in  point  is  that  of  the  Lewis  range  in  Montana, f 
where  the  altitudes  bear  these  relations.  But  these  relations  do  not  hold 
for  the  mountains  of  Central  China ;  their  heights  and  lows  are  related  to 
upwarps  and  downwarps,  which  are  not  coincident  with  the  complex  and 
intruded  structures  of  Permo-Mesozoic  time,  but  are  everywhere  sculptured 


*  European  Studies,  B.  Willis,  Carnegie  Institution  of  Washington  Year  Book  No.  4.  Bau  und  Bild 
der  Karpaten,  by  V.  Uhlig,  in  Bau  und  Bild  Oesterreichs,  Wien,  1903. 

t  Stratigraphy  and  Structure  of  the  Lewis  and  Livingston  Ranges,  B.  Willis,  Bull.  G.  S.  A.,  vol.  xni, 
P-  346- 


WARPING   AND   FAULTING.  105 

with  the  mature  erosion  forms  of  the  Ts'in-ling  stage.  And  strictly  accord- 
ing to  the  later  warping  and  faulting  are  the  depths  of  the  young  canyons, 
which  pursue  courses  that  are  in  some  measure  consequent  on  the  slopes  of 
recent  upwarps,  but  in  general  inconsequent  to  the  older  structure.  The 
present  relations  of  altitudes  and  folds  show  that  tectonic  elevations  of 
Permo-Mesozoic  age  have  given  place  to  warped  elevations  of  modern  age  ; 
and  the  physiographic  record  makes  it  clear  that  one  or  more  periods  of 
little  or  no  elevation  intervened. 

The  present  topographic  cycle,  which  we  may  call  either  the  Fon-ho  or 
the  Yang-tz'i  cycle,  is  characterized  by  the  development  of  basins,  warped 
surfaces,  fault-scarps,  and  great  mountain  ranges,  and  consequently  also  by 
youthful  erosion  forms  and  extensive  plains  of  aggradation.  The  scarp, 
the  canyon,  and  the  alluvial  fan  are  the  marked  accents  of  the  cycle  and 
are  the  noted  features  of  Asiatic  topography.  The  warped  surface  that 
bears  the  sculpture  of  a  preceding  cycle  is  also  of  general  occurrence,  but 
has  less  often  been  noted. 

The  map,  plate  8,  comprising  the  Chinese  Empire  and  parts  of  adja- 
cent regions,  represents  the  distribution  of  elevated  and  depressed  areas. 
It  is  based  on  actual  altitudes  and  is  a  rough  hypsometric  map;  but  it  is  not 
accurate  in  that  sense,  because,  on  the  one  hand,  the  number  of  points  whose 
altitude  is  known  is  inadequate  to  accuracy,  and  on  the  other,  effects  of  ero- 
sion have  been  disregarded  intentionally.  The  surface  which  the  contours 
represent  constitutes  the  basins,  slopes,  ranges,  and  plateaus  as  they  would 
exist  if  a  plain  had  been  warped  and  dislocated  and  had  not  been  eroded. 
The  map  thus  expresses  the  hypothesis  that  Asia  was  reduced  to  a  general 
peneplain  and  has  since  been  warped  in  a  manner  to  produce  differences  of 
elevation  exceeding  6,000  meters,  20,000  feet.  In  the  preceding  pages  and 
in  volume  i,  part  i,  of  this  publication  I  have  given  the  facts  which  indicate 
that, in  the  districts  we  observed,  the  warping  has  taken  place  chiefly  during 
late  Tertiary  and  Quaternary  times.  My  present  purpose  is  to  extend  the 
inferences  regarding  modern  mountain  growths  to  regions  that  are  genetic- 
ally related  to  those  which  we  saw. 

First,  with  reference  to  the  region  of  the  great  alluvial  plain  of  eastern 
China,  it  is  usually  recognized  that  it  is  an  area  of  depression,  a  downwarp 
extending  from  northern  Manchuria  to  Hu-nan  and  filled  with  alluvium 
of  the  great  rivers  that  debouch  from  the  western  and  southern  mountains. 
We  have  shown  that  Shan-tung,  the  peninsula  of  the  Eastern  Mountains, 
has  since  the  episode  of  the  early  Tertiary  faulting  stood  as  a  horst  in  the 
sinking  region,  its  margins  being  bent  down  but  its  interior  not  notably 
raised  in  the  process.* 

*  Research  in  China,  vol.  I,  part  I,  page  83. 


IO6  RESEARCH   IN   CHINA. 

The  eastern  margin  of  this  downwarp  lies  in  the  Yellow  Sea,  possibly 
between  the  point  of  Korea  and  Shanghai.  The  mountains  of  southeastern 
China  may  be  said  to  limit  it  on  the  southeast.  The  Yang-tz'i  defines  it 
northeast  from  the  Tung-ting  lake.  The  hills  of  An-hui  and  Hu-pe'i  appear 
to  be  within  its  area. 

The  western  margin  of  the  downwarp  is  the  slope  of  the  mountains, 
comprising  the  Khingan  range  in  the  north,  the  so-called  plateau  of  Shan-si 
in  a  mid-stretch,  and  the  mountains  of  eastern  Hu-pe'i  further  south.  Von 
Richthofen  described  the  limit  between  the  plain  and  the  mountains  as  a 
fault,  which  appears  on  his  map,  Versuch  einer  Tektonischen  Karte  des 
nordlichen  Chinas,  as  the  Khingan  Linie.*  He  does  not  cite  any  evidence 
of  faulting  on  the  line  itself,  it  being  drawn  indeed  in  the  plain  of  alluvium  ; 
and  according  to  our  observations  on  three  different  sections  the  passage 
from  the  plain  to  the  mountains  is  a  zone  of  warping,  not  a  line  of  disloca- 
tion. Where,  in  latitude  49°,  the  Siberian  railroad  descends  to  the  Sungari, 
the  eastern  slope  of  the  Khingan  is  a  tilted,  dissected,  but  unbroken  pene- 
plain. Where  the  Sha-ho,  in  latitude  39°,  has  cut  its  autogenous  valley, 
and  the  hills  about  T'ang-hien  lie  half-buried  in  the  plain,  the  effects  of 
modern  warping  are  obvious.  Normal  faulting,  though  present  in  the 
Ning-shan  basin,  occurred  at  a  remote  Tertiary  date,  and  erosion  has 
reversed  the  relief  to  which  it  gave  rise.  Again,  in  latitude  31°,  where  the 
Yang-tz'i  emerges  from  its  profound  gorges  at  I-chang,  the  mountain  slope 
that  faces  the  far-spreading  river  plain  is  a  tilted  surface  of  erosion,  showing 
a  continuous  stratum  of  Carboniferous  limestone,  which  toward  the  base  is 
overlain  by  the  K'ui-chou  red  beds  in  appropriate  stratigraphic  sequence. 
It  is  a  warped  surface,  not  a  fault;  and  there  is  no  evidence  that  it  is  limited 
by  a  fault  at  the  base. 

This  zone  of  warping  was  crossed  by  von  Richthofen  along  two  routes 
of  travel  in  Shan-si;  the  one  in  latitude  33°,  northwest  of  "Hwai-king-fu;" 
the  other  in  latitude  38°,  on  the  great  road  from  T'ai-yiian-fu  to  the  eastern 
plain.  In  the  former  traverse  he  ascended  to  the  plateau  over  a  mono- 
clinal  flexure  on  an  erosion  surface  that  is  sculptured  on  Carboniferous 
shales  and  Sinian  limestones!  and  that  forms  spurs  between  deep  gulches. 
The  steep  slopes  of  the  spurs  end  in  a  line  and  thus  simulate  a  fault-scarp, 
but  the  structure  is  that  of  a  simple  flexure  and  is  so  described  by  the  trav- 
eler. At  the  more  northerly  crossing  von  Richthofen  observed  step-faulting 
which  he  describes  as  follows  :$ 

After  having  observed  the  structure  of  the  mountains  in  southern  Shan-si,  it  was 
for  me  a  matter  of  no  slight  interest  to  see  in  what  manner  the  horizontal  strata  of  the 
plateau  might  break  away  or  sink  toward  the  Great  Plain.  As  we  have  seen,  the  plateau 


*China,  vol.  II.         f  Ibid.,  vol.  n,  p.  407.         I  Ibid.,  vol.  H,  pp.  440-442. 


THE   KHINGAN   PLEXURB.  1 07 

ended  on  the  south  with  a  short  monoclinal  flexure.  Were  that  to  be  the  case  in  this 
region  the  plateau  must  extend  far  toward  the  east;  but  this  did  not  seem  probable,  as 
according  to  all  accounts  I  was  near  the  end  of  the  anthracite  region.  In  fact  I  came 
sooner  than  I  expected  to  the  first  fault.  The  general  relation  was  indeed  difficult  to  under- 
stand in  a  single  rapid  traverse,  but  it  was  soon  clear  that  the  plateau  fell  off  in  steps, 
which  are  occasioned  by  faults  along  a  great  fault  zone,  which  runs  from  north  to  south 
and  is  in  part  connected  with  gentle  flexures.  If  one  regards  the  attitude  of  the  strata  in 
individual  cases,  one  often  finds  it  confusing,  for  locally  the  limestone  dips  in  various 
directions  and  with  different  angles.  This  is  particularly  noticeable  in  the  descent  from 
each  separate  step.  But  if  one  looks  back  toward  the  west  from  a  little  distance  and 
regards  the  steep  slope  of  the  ridge  which  has  just  been  crossed,  one  is  surprised  to  observe 
in  general  only  horizontal  lines  of  stratification.  In  every  such  case  one  is  on  that  portion 
of  the  surface  which  has  sunk  down  with  reference  to  the  higher  steps.  The  variations 
in  the  altitude  of  the  strata  may  possibly  be  related  in  part  to  the  displacement  of  the 
beds  in  the  tremendous  process  of  faulting,  or  may  in  part  be  due  to  caving  in,  there  being 
in  some  places  caverns,  which  occur  especially  in  the  Rauchwackc. 

While  these  observations  are  avowedly  incomplete  and  do  not  carry 
conviction  to  the  reader,  the  conclusion  is  not  inconsistent  with  the  warping 
observed  elsewhere.  Warping  and  faulting  are  related  phenomena;  the 
latter  is  an  extreme  effect  of  a  concentrated  stress  set  up  in  consequence 
of  the  former,  and  may  be  looked  for  wherever  the  zone  between  an  area 
of  depression  and  one  of  elevation  is  relatively  narrow  as  compared  with  the 
difference  of  altitude  resulting  from  the  movement. 

I  conclude  that  the  weight  of  evidence  shows  that  the  passage  from 
the  depressed  region  to  the  elevated  plateaus  of  the  mountainous  area  is 
by  a  warped  surface  more  generally  than  by  a  dislocation,  and  that  the 
' '  Khingan  I,ime "  is  to  be  regarded  as  a  zone  of  monoclinal  flexure,  not  as 
a  fault. 

The  depressed  region  just  described  is  one  of  the  eastern  or  outer 
provinces  of  the  continent.  While  it  has  subsided  somewhat,  the  region 
on  the  northwest  has  risen  considerably  more.  The  physiographic  record 
shows  that  up  to  the  close  of  the  Hin-chou  epoch  the  difference  of  altitude 
between  the  two  was  no  more  than  that  of  a  gentle,  continuous  slope,  but 
since  that  time  it  has  been  increased  to  6,000  or  7,000  feet,  1,800  or  2,100 
meters,  on  a  moderate  allowance  of  5,000  feet  for  the  elevation  of  the 
T'ang-hien  surface  in  the  plateaus  of  Shan-si,  and  of  1,000  to  2,000  feet, 
300  to  600  meters,  for  the  depression  of  the  same  surface  beneath  the 
Great  Plain. 

This  difference  in  altitude  has  developed  within  the  late  Pliocene  and 
the  Quaternary;  probably  chiefly  during  the  latter.  There  are  two  con- 
ceptions of  the  manner:  The  region  which  is  high  may  be  regarded  as  a 
horst,  which  has  stood  firm  while  the  adjacent  area  has  sunk  down  below 


108  RESEARCH   IN   CHINA. 

its  level;  and  simultaneously  the  ocean  basins  have  so  deepened  that  sea- 
level  has  been  lowered  5,000  feet,  1,500  meters.  Or,  there  have  been  both 
positive  and  negative  movements — not  sinking  only,  but  rising  also — and 
consequently  readjustments  of  sea-level  and  of  altitudes  of  various  areas. 

The  element  of  time  is  important  in  the  hypothesis  which  ascribes 
all  epeirogenic  changes  of  level  to  subsidence  in  obedience  to  gravity;  but 
the  movements  in  Asia  are  so  recent  that  time  fails.  The  physiographic 
history  of  the  mountains  of  Shan-si  is  plain  and  consistent.  The  young 
slopes  and  scarps  and  canyons  are  obvious  facts.  However  we  may 
differ  in  a  reasonable  estimate  of  their  possible  age,  we  can  not  assign  to 
them  an  antiquity  such  that  during  their  development  sea-level  might 
have  sunk  5,000  feet,  1,500  meters.  To  do  so  would  not  only  contradict 
the  direct  evidence  of  comparison  with  topographic  features  elsewhere, 
which  are  definitely  dated  by  relation  to  late  Tertiary  sediments,  but 
would  require  explanation  of  the  absence  of  a  marine  record  where  there 
is  an  erosion  record  instead.  This  question  enters  into  the  study  of  the 
highlands  of  Asia  as  a  fundamental  distinction  between  two  very  differ- 
ent interpretations  of  the  orogeny  and  epeirogeny  of  the  continent.  My 
views  are  more  fully  stated  in  the  following  chapter  on  the  hypotheses  of 
continental  structure.  It  suffices  here  to  state  that  I  hold  it  to  be  true 
that  when  some  masses  sink  notably,  whether  in  continental  or  oceanic 
regions,  other  masses  rise  notably;  while  some  parts  of  Asia  have  certainly 
subsided  during  the  latest  movements,  other  parts  have  risen,  and  the 
upward  movements,  which  are  measured  by  many  thousand  feet,  are  greatly 
in  excess  of  the  downward  movements  within  the  continent. 

The  mountainous  region  of  northwestern  China  may  be  said  to  consist 
of  the  Khingan  range  north  of  latitude  40°,  where  that  height  is  the  margin 
of  the  Mongolian  plateau  simply,  and  of  the  various  ranges  of  Chi-li  and 
Shan-si,  which  as  a  group  are  distinct  from  the  Mongolian  plateau.  Among 
the  latter  are  the  Nan-k'ou  range  northwest  of  Peking,  the  Wu-t'ai-shan, 
and  the  plateau  of  Shan-si  with  the  Ho-shan.  The  physiographic  history 
of  these  mountains  and  the  reasons  for  believing  them  to  have  been  elevated 
during  the  Fon-ho  epoch  of  the  Quaternary  have  been  sufficiently  set  forth. 

Northwest  of  the  mountain  system  of  Chi-li  and  Shan-si  is  a  depressed 
zone  characterized  by  the  basins  of  Ta-tung-fu,  latitude  40°;  of  Hin-ch6u, 
latitude  38°  30';  of  T'ai-yiian-fu,  latitude  37°  30';  of  P'ing-yang-fu,  latitude 
36°;  and  of  the  Wei  valley,  latitude  34°  30'.  The  last  stretches  far  to  the 
west,  north  of  the  Ts'in-ling-shan,  and  is  related  to  the  depression  of  Kan- 
chou  and  Sii-chou,  which  lies  along  the  northeastern  border  of  the  Nan- 
shan.  Von  Richthofen  describes  the  basin  of  Ta-tung-fu.*  We  refer  to 


*  China,  vol.  n,  p.  359. 


GRABEN  Otf  SHAN-SI.  IO9 

our  own  account  of  the  others  in  volume  i,  except  with  reference  to  the 
most  northwestern,  for  which  Loczy  may  be  consulted.* 

The  zone  of  these  basins,  comprising  an  arc  which  surrounds  Mongolia 
and  Ordos  on  the  southeast  and  which  is  more  than  1,500  miles,  2,400  kilo- 
meters long,  is  a  downwarp  with  reference  to  the  mountain  regions  that 
adjoin  it.  It  is  related  to  the  heights  southeast  and  south  of  it  by  warped 
surfaces,  which  are,  however,  faulted  throughout  considerable  stretches, 
producing  great  scarps  several  thousand  feet  high  that  face  inward  toward 
central  Asia.  The  ascent  toward  the  northwest  or  north  is  generally  by 
long,  gently  inclined  slopes,  but  locally  by  more  steeply  tilted  surfaces,  and 
occasionally  by  a  fault.  The  O-shan  fault  in  central  Shan-si,  which  defines 
the  Fon-ho  graben  on  the  west,  is  the  only  one  which  has  been  definitely 
recognized  on  that  side. 

In  its  internal  displacements  the  zone  of  depression  is  not  simple.  The 
basins  lie  en  echelon  and  are  separated  by  moderate  upwarps  that  traverse 
the  zone  diagonally  or  directly  as  the  case  may  be.  The  dividing  ridges 
may  be  enumerated  as  follows:  the  Man-t'o-shan,  separating  the  basins  of 
Ta-tung-fu  and  Hin-chou;  the  Shi'-ling,  south  of  the  latter;  the  Si-yau-ling 
and  Si-sin-ling  in  central  Shan-si,  between  the  T'ai-yiian-fu  and  P'ing-yang- 
fu  basins;  and  the  lesser  upwarp  dividing  the  Fon-ho  from  the  salt  lake 
basin  in  southern  Shan-si.  These  details  of  warping  are  characterized  by 
the  youthful  features  of  the  Fon-ho  epoch,  namely,  the  mantle  of  Huang-t'u 
formation  not  yet  removed,  the  relation  to  antecedent  streams,  and  the 
characteristic  deep  gorges. 

This  zone  is  one  of  the  major  structure  lines  of  the  continent,  which  is 
recognized  in  modern  displacements  by  relatively  slight  elevation  above  sea. 
It  agrees  in  general  trend  with  the  directions  of  folding  of  pre-Cambrian  as 
well  as  of  Permo-Mesozoic  deformation.  It  was  apparently  the  littoral  of 
pre-Cambrian  seas,  a  strip  bordering  the  downwarps  in  which  the  Wu-t'ai 
and  Hu-t'o  sediments  accumulated  to  great  thickness;  but  after  they  were 
folded  it  became  part  of  the  land  across  which  the  Sinian  sea  transgressed 
and  over  which  Carboniferous  continental  deposits  more  or  less  generally 
accumulated.  During  the  long  quiescence  of  the  continent  it  does  not 
appear  to  have  been  a  distinctive  line;  in  the  Permo-Mesozoic  disturbance 
it  was  folded;  and  in  the  recent  extraordinary  diastrophism  it  has  again 
become  manifest  in  marked  differences  of  elevation. 

Mongolia  lies  northwest  of  the  basins  of  Shan-si  and  north  of  the 
depression  of  Shen-si  and  Kan-su.  It  is  a  region  throughout  which  separate 
ranges  rise  from  great  expanses  of  Pliocene  and  Quaternary  desert  waste,  a 
region  in  which  the  evidences  of  structure  and  of  physiographic  development 

*  Reise  des  Grafen  Szechenyi,  vol.  i,  p.  499  et  seq. 


IIO  RESEARCH   IN  CHINA. 

are  disconnected.  They  have  not  been  observed  from  the  point  of  view  we 
are  now  taking.  The  available  data  relating  to  the  structural  trends,  the 
isolated  ridges,  the  desert  plains,  and  the  deep  depressions  are  gathered  by 
Suess  into  a  masterly  description  in  the  third  volume  of  Das  Antlitz  der 
Erde.  The  acute  features  of  dislocation  and  erosion;  the  warping  of  the 
Tertiary  Gobi  deposits  and  their  occurrence  high  on  the  ranges  from  which 
they  extend  to  basins  below  sea-level:  these  suffice  to  bring  the  period 
of  diastrophism  to  which  the  relief  is  due  within  the  later  Tertiary  and 
Quaternary.  I  quote  Huntington,  who  has  studied  the  western  part  of 
the  vast  region.*  In  regard  to  the  Zorabad  basin,  he  says: 

Apparently  it  was  first  occupied  by  the  sea  and  later  became  dry  land.  Then,  by 
the  warping  of  the  earth's  crust,  it  was  converted  into  a  lake,  which  in  time  was  drained 
by  the  cutting  of  a  gorge.  As  the  water  of  the  lake  receded,  gravel  was  washed  in  from 
the  sides  and  covered  the  lake  deposits.  Since  that  time  the  gorge  at  the  outlet  has  been 
cut  deeper,  the  various  deposits  have  all  been  more  or  less  dissected,  and  terraces  have 
been  formed.  At  intervals  during  the  progress  of  these  events,  warping  has  gone  on  in 
such  a  fashion  that  the  size  of  the  basin  has  continually  diminished  and  all  the  deposits 
except  the  most  recent  gravels  have  been  warped  along  the  edges,  although  apparently 
remaining  horizontal  in  the  center  of  the  basin.  Most  of  this  history  probably  belongs  to 
Tertiary  times,  although  the  dissection  of  the  lake  deposits  and  the  formation  of  the  terraces 
almost  certainly  belong  to  the  present  geological  era. 

In  order  to  understand  the  geological  history  of  Persia  it  will  be  necessary  to  ascertain 
to  what  extent  a  similar  series  of  events  has  occurred  in  other  basins.  What  few  facts 
are  known  indicate  that  the  history  of  all  the  basins  is  similar  to  that  of  Zorabad,  with  the 
exception  of  the  lake  episode.  The  only  lakes  of  which  we  have  record  in  the  other  basins 
occurred  at  a  later  time  and  were  due  to  changes  of  climate  rather  than  to  warping  of  the 
crust. 

The  mountains  of  Trans-Baikalia  constitute  a  group  which  is  clearly 
distinguished  from  the  Gobi  region  on  the  south,  the  plateaus  to  the  north- 
east, and  the  plains  of  the  amphitheater  of  Irkutsk  to  the  northwest. 
Whereas  the  Gobi  is  a  region  of  displacement  and  aggradation  and  the 
plateaus  are  one  of  regional  uplift  and  the  plains  one  of  regional  depression, 
Trans-Baikalia  is  characterized  by  elevation,  faulting,  and  denudation.  I 
have  already  cited  the  evidence  adduced  by  Suess  for  ascribing  to  the  basin 
of  Lake  Baikal  a  late  Tertiary  date,  and  stated  that  the  conclusion  may  be 
extended  to  the  ranges  of  Trans-Baikalia.  This  applies  to  the  principal 
heights  in  the  northeastern  district.  It  is  doubtful  how  far  the  Tertiary 
uplift  may  be  traced  in  the  adjoining  plateau  district,  where  the  sharply 
defined  canyon  of  the  Lena  has  the  aspect  of  a  Quaternary  gorge.  I  am 
inclined  to  regard  the  Trans-Baikal  mountains  as  an  insular  faulted  upwarp, 
like  Shan-tung,  and  to  infer  that  the  plateau  region  is  of  later  elevation. 

*  Explorations  in  Turkestan,  Carnegie  Institution  of  Washington  Publication  No.  26,  p.  242. 


WARPING   IN   CENTRAL   CHINA. 


Ill 


From  Siberia  we  may  return  to  central  China. 

The  Ts'in-ling-shan  rises  from  the  valley  of  the  Wei'  by  a  steep  warped 
surface  and  fault-scarp,  which  we  ascribe  to  the  Quaternary  (Fon-ho,  or 
Yang-tzi)  epoch.  Among  the  heights  of  the  range  we  recognize  a  mature 
surface,  which  we  attribute  to  the  Ts'in-ling  cycle  of  late  Tertiary  time. 
It  extends  beyond  the  Ts'in-ling  range,  across  the  Han  watershed  to  the 
middle  Yang-tzi  region,  and  is  strongly  warped.  The  great  features  to 
which  the  warping  gives  rise  are  four:  the  Ts'in-ling-shan,  the  Han  down- 
warp,  the  Kiu-lung-shan  between  the  Han  and  the  Yang-tz'i,  and  the  present 
basin  of  Ssi-ch'uan. 

The  Ts'in-ling-shan  is  a  long  upwarp,  the  eastern  continuation  of  the 
Kuen-lung;  it  attains  a  general  elevation  of  7,000  to  9,000  feet,  2,100  to 
2,700  meters,  and  in  the  special  accent,  the  Ta-pai-shan,  rises  to  12,000  feet, 
3,600  meters.  On  the  south  it  sinks  to  the  Han  downwarp,  which  is  a  broad 
depression  having  summit  altitudes  of  about  3,000  feet,  900  meters,  which 
are  modified  by  local  upwarps  that  probably  reach  6,000  feet,  1,800  meters, 
and  by  two  pronounced  downwarps,  those  of  Han-chung-fu  and  Hing-an-fu. 
The  floors  of  these  basins  are  plains  of  aggradation,  that  of  Han-chung-fu 
approximately  i  ,500  feet,  450  meters,  that  of  Hing-an-fu  very  nearly  800  feet, 
240  meters,  above  sea;  but  the  Ts'in-ling  erosion  surface  sinks  beneath  the 
Quaternary  deposit,  being  depressed  to  a  still  lower  level.  At  Hing-an-fu 
the  coarse  gravels,  sands,  and  clays  form  bluffs  along  the  Han.  The  Red 
Basin  of  Ss'i-ch'uan  is  a  downwarp  like  the  two  mentioned,  except  that  it  is 
very  much  larger,  and,  as  the  remarkable  delta  plain  of  Chung-t'ing-fu 
shows,  is  a  region  of  continued  subsidence  and  aggradation.  The  Kiu-lung- 
shan  is  an  upwarp  containing  summit  altitudes  of  8,000  to  possibly  12,000 
feet,  2,400  to  3,600  meters.  It  lies  between  the  basin  of  Ss'i-ch'uan  which  is 
on  the  west  and  the  great  downwarp  of  the  lower  Yang-tz'i,  its  warped  sur- 
face passing  beneath  the  flood-plain  at  I-chang.  On  the  north  it  is  bounded 
by  the  Han  downwarp.  Southward  it  extends  across  the  Yang-tzi,  its 
surface  declining  to  depressions  that  are  not  yet  observed. 

The  warped  surface  of  Central  China,  which  may  thus  be  analyzed, 
exhibits  differences  of  altitude  of  12,000  feet.  It  is,  so  far  as  we  saw  it  and 
we  believe  generally,  an  erosion  surface  which,  while  retaining  notable  relief, 
assumed  mature  features  by  the  close  of  the  Tertiary  period.  It  may  have 
persisted  at  a  low  elevation  into  Quaternary  time.  During  the  Quaternary 
it  has  been  warped,  giving  rise  to  the  great  mountain  chains  and  extensive 
basins  that  now  exist.  The  warping  characterizes  the  Yang-tzi  epoch  of 
erosion,  and  the  youthful  aspect  of  the  canyons  of  that  cycle  is  the  ground 
for  the  inference  that  the  movement  did  not  assume  notable  proportions 
until  Quaternary  time. 


112  RESEARCH   IN   CHINA. 

The  elevation  of  the  Ts'in-ling-shan  is  continued  toward  the  west  by  the 
Kuen-lung  and  the  Nan-shan,  which  rise  to  much  greater  heights;  but  the 
physiographic  aspect  appears  to  change.  The  broad  upwarp  which,  in 
longitude  108°  east,  is  100  miles,  160  kilometers,  across  without  a  break,  is 
replaced  by  several  ranges  separated  by  valleys  and  basins.  The  effects  of 
warping  are  more  complex  and  are  probably  accented  by  faulting.  The 
type  is  rather  that  of  the  Gobi  than  that  of  central  China. 

Tibet  and  the  Himalayas  finally  claim  attention. 

The  Alps  of  eastern  Tibet,  the  Yung-ling,  tower  above  the  lowlands  of 
Ssi'-ch'uan  in  wonderful  grandeur  to  an  extreme  altitude  of  7,000  meters. 
We  have  no  definite  knowledge  of  the  physiographic  aspects  of  this  great 
mountain  face,  but  in  one  respect  it  differs  markedly  from  the  southern 
front  of  the  Himalayas,  with  which  it  may  naturally  be  compared.  The 
rivers  that  drain  the  Himalayas  flow  directly  across  the  range,  after  the 
manner  of  consequent  streams,  which  have  developed  at  right  angles  to  the 
trend  and  been  extended  by  headwater  erosion  in  consequence  of  a  com- 
bination of  favoring  conditions.  The  rivers  of  the  Tibetan  Alps,  on  the 
contrary,  flow  southwest  between  high  ranges,  which  direct  them  in  courses 
diagonal  to  the  lines  of  shortest  descent  toward  the  basin  of  Ssi'-ch'uan. 
They  thus  have  the  character  of  streams  which  are  consequent  upon  a 
folded  or  faulted  surface  and  take  their  own  way  down  the  axial  lines  of  the 
major  depressions.  There  is  thus  reason  to  regard  this  slope  as  being 
composed  of  successive  upwarps  or  fault-blocks,  which  lie  en  echelon  and  sink 
at  their  southeastern  ends  to  the  lowland  of  Ssi'-ch'uan.  The  character  is 
expressed  in  the  contours  which  define  the  slope  north  of  latitude  30°  and 
about  the  meridian  of  103°  east. 

Toward  the  west  and  south  the  great  ranges  of  the  Tibetan  Alps  are 
bounded  apparently  by  the  broad  plateau,  which  is  deeply  incised  by  the 
canyons  of  the  upper  Yang-tzi'  and  the  Mekong  and  their  several  branches. 
The  parallelism  of  these  great  rivers  west  of  the  one-hundredth  meridian 
may  be  an  effect  of  unknown  tectonic  lines,  but  it  is  with  equal  reason 
explicable  as  the  growth  of  autogenous  canyons  on  a  uniform  slope.  The 
meanders  of  the  Yang-tz'i  in  latitude  25°  north  may  be  attributed  to 
capture  across  a  fault-scarp. 

The  western  part  of  the  map  includes  the  vast  highland  of  Tibet  and 
its  bounding  ranges,  the  Altin-tagh  on  the  north  and  the  Himalayas  on  the 
south.  The  structural  character  of  the  plateau  is  not  known,  but  it  appears 
to  be  that  of  a  mass  which  has  been  forced  above  a  position  of  equilibrium 
and  which  has  consequently  broken  into  blocks  that  have  suffered  diverse 
displacements.  The  depressions  are  deeply  filled  with  Pliocene  and  Qua- 
ternary sediments. 


WARPING   IN  CENTRAL  ASIA.  113 

The  limiting  ranges  hold  apparently  homologous  relations  to  the 
plateaus;  but  they  differ  greatly  in  history  and  structure.  The  Altin-tagh, 
occupying  part  of  the  northern  Tethys,  was  folded  primarily  in  the  Permo- 
Mesozoic  revolution,  and  its  essential  structures  thus  date  from  a  some- 
what remote  time.  The  Himalayas  did  not  suffer  compression  till  the 
beginning  of  the  period  of  diastrophism  that  marks  the  late  Tertiary  and 
Quaternary.  The  Altin-tagh  seems  to  rise  from  the  Tarim  basin  as  a  con- 
tinuation of  the  eroded  surface  which  plunges  beneath  the  Gobi  deposits 
of  the  desert;  it  resembles  apparently  the  warped  surface  by  which  the 
Shan-si  mountain  region  sinks  beneath  the  plains  of  eastern  China;  and 
though  possibly  in  some  sections  broken  by  normal  faults,  it  does  not  differ 
from  other  mountain  slopes  of  Asia.  The  Himalaya  range,  on  the  other 
hand,  is  unlike  them.  It  is  separated  from  the  plains  at  its  southern  base 
by  thrusts  of  great  magnitude,  which  dip  beneath  the  upraised  mass.  The 
effect  is  as  if  the  range  were  pushed  southward — were  overthrust;  it  may 
equally  well  be  expressed  by  the  statement  that  the  lowlands  are  pushed 
northward — are  underthrust.  Since  the  overthrusting  or  underthrusting, 
whichever  is  the  dominant  fact,  involves  movement  on  an  inclined  plane, 
the  mechanical  condition  is  that  which  would  result  from  driving  a  wedge 
under  the  range.  Either  the  range  must  be  raised  or  the  wedge  must  be 
depressed,  or  both  movements  may  occur.  In  discussing  the  analogous 
case  of  the  Lewis  range  of  the  Rocky  Mountains  in  Montana,  I  have  shown 
that  an  elevation  of  3,400  feet  is  probably  attributable  to  a  displacement 
of  7  miles  on  the  flat  thrust  which  underlies  the  Algonkian  strata.*  The 
thrusts  beneath  the  Himalayas  are  apparently  even  more  important  factors 
in  the  relative  elevation  of  the  mountain  mass.  Among  Asiatic  mountains 
the  Himalayas  thus  present  a  unique  case  of  mechanical  relations. 

The  elevation  of  the  Tibetan  plateau  (Isle  Tibet)  is  apparently  an  effect 
of  the  underthrusting,  to  which  we  may  attribute  some  considerable  part 
of  the  altitude  of  the  Himalayas.  I  conceive  that  the  plateau  is  the  surface 
of  a  deep-seated,  strongly  compressed  sub-Tibetan  mass. 

*  Stratigraphy  and  Structure,  Lewis  and  Livingston  Ranges,  Montana,  Bull.  G.  S.  A.,  vol.  xni,  p.  345. 


RESEARCH  IN    C 


PLATE    7 


ALTITU  DES    IN 
METERS 


Base  from  Stielers  Atlas,  19 
maps  62  and  64  by  C.  Baric 
Altitudes  compiled  from  a 


Structure  and  physiography 
interpreted  by  Bailey  Willis 


EARTH  SOENCES 


